What happens to my phone number when I switch broadband in 2026?
You can keep your existing UK phone number when switching broadband providers in 2026, but the answer to "what happens to my number" is more nuanced than it used to be because of the parallel January 2027 PSTN switch-off and the transition to Digital Voice. Number portability itself remains protected by Ofcom regulation and works seamlessly under One Touch Switch. However, your number is also moving from the analogue PSTN to a digital IP-based service in the same broad timeframe as your switch, which means there are practical considerations around power-cut protection, telecare devices, and battery backup that didn't exist a few years ago. This guide is the comprehensive 2026 walkthrough of everything that happens to your phone number during a UK broadband switch, plus the wider digital-voice transition that will reach every remaining UK landline by 31 January 2027.
The 2026 number portability answer in 60 seconds
You can keep your UK landline number when switching broadband providers in 2026 - this is your right under Ofcom regulation and the new provider handles the porting automatically as part of the One Touch Switch process. Number porting typically takes 10-15 working days alongside the broadband activation; the visible customer experience is that your number simply continues to work with the new provider. However, your number is also being migrated from the legacy analogue PSTN copper network to a digital IP-based service called Digital Voice (BT branding), Sky Voice, Virgin Media Voice, or similar branded variants depending on your provider. This separate migration is happening across all UK landlines and must complete by 31 January 2027 when the PSTN switches off entirely. By July 2025 the number of UK PSTN customers had already fallen from 5.2 million (July 2024 baseline) to 3.2 million. If you switch broadband in 2026, your new service will almost certainly include Digital Voice rather than analogue landline; this means you'll need broadband connectivity for calls (the line goes via your router), Ofcom requires providers to give at least 1 hour of battery backup for emergency calls in a power cut, and any telecare or alarm devices may need upgrading. This guide covers each step in detail.
The 2026 UK number portability and Digital Voice landscape
Three regulatory developments shape the 2026 UK landline number environment: number portability has been a protected consumer right under Ofcom regulation for over two decades and continues to apply at every UK broadband switch under One Touch Switch; the Public Switched Telephone Network (PSTN) switch-off, an industry-led migration from analogue copper to digital IP-based voice service, has a confirmed hard deadline of 31 January 2027; and Ofcom power-cut resilience requirements ensure that even on the new digital infrastructure customers retain access to emergency services for at least one hour during local power outages.
The headline scale: according to House of Commons Library research published April 2026, the number of UK landline customers on the legacy PSTN fell from 5.2 million in July 2024 to 3.2 million in July 2025 - approximately 2 million UK households migrated to Digital Voice over a single year as the major providers (BT, Sky, Virgin Media, TalkTalk, Vodafone) accelerated their customer-by-customer migration programmes. BT alone had migrated over 2 million customers to its Digital Voice service by 2026 per Which? coverage; the remaining 3.2 million PSTN customers across all providers are expected to migrate progressively through 2026 to meet the January 2027 deadline.
Number portability: Protected by Ofcom regulation since 1996. You can keep your existing UK landline number when switching to almost any other UK provider; the new provider handles the porting via the One Touch Switch (OTS) process and the parallel number portability framework.
PSTN switch-off date: 31 January 2027 confirmed and "locked in" per Openreach (House of Commons Library briefing April 2026). This is a hard deadline; there is no extension, no fallback, and no grace period. Originally December 2025, pushed back twice to address vulnerable customer protections.
Stop-sell since September 2023: Openreach stopped selling new PSTN and ISDN lines in September 2023. Any new broadband orders since then have been delivered on digital infrastructure with Digital Voice handling the phone service.
Digital Voice naming: Different providers use different branded names: BT Digital Voice (the most common), Sky Voice (sometimes called Sky Talk Internet Calls), Virgin Media Voice, TalkTalk Digital Voice, Vodafone digital phone service. All of these are essentially the same technology (Voice over Internet Protocol, VoIP) running over your broadband connection.
Ofcom emergency service requirement: Phone providers must take measures to ensure uninterrupted access to emergency services for at least 1 hour during a power cut. This typically means a battery backup unit (BBU) for the router, free of charge for vulnerable customers; voluntary or paid for other customers who request one.
Number portability fee: Generally free to the customer. Providers may charge each other behind the scenes for the technical porting work but cannot pass these charges to customers.
The combined effect for someone switching broadband in 2026 is that two related but separate processes happen at the same time: (1) your phone number ports from the losing provider to the gaining provider via the established Ofcom number portability framework, supported by the OTS process for coordination; and (2) your service migrates from analogue PSTN to digital IP-based Digital Voice as part of the wider industry transition. In most cases both happen invisibly to the customer - the visible experience is that you switch broadband, your phone number continues to work, and afterwards your phone runs through the new provider's router rather than a separate copper line. The parts of this guide below cover each aspect in turn.
Keeping your existing landline number when switching
The default outcome when switching UK broadband providers is that you keep your existing landline number. You don't need to take any special action to request this; the new provider handles the number porting as part of the standard OTS process based on the information you provide at sign-up. However, there are some practical considerations and edge cases worth understanding so you can confirm everything is in order before activation day.
Switching between major UK providers: Number portability works seamlessly between BT, Sky, Virgin Media, Vodafone, TalkTalk, EE, Plusnet, NOW Broadband, and most altnets. All major providers participate in the standard number portability framework.
Switching from Openreach to Virgin Media or vice versa: Cross-network porting works. Your existing number is moved from one network's number-routing infrastructure to the other's; the customer experience is identical to a same-network port.
Switching to or from altnets (CityFibre retail brands, YouFibre on Netomnia, Hyperoptic, Community Fibre, toob, etc.): Most altnets participate in number portability via their wholesale network operators. Confirm at sign-up that your existing number can be ported; the gaining provider's customer service will check this against the central number portability databases.
Switching while keeping the same provider but changing service: Number is preserved by default. Some upgrades (FTTC to FTTP, broadband to bundled service) may trigger an internal account migration but the number stays.
Geographic number portability: UK landline numbers are tied to specific geographic exchange areas (the leading "01" or "02" digits indicate the area). In practice, geographic portability rules require the receiving provider to be able to serve a number from the original geographic area. In almost all cases for residential broadband switches at the same address, this works without issue. If you've moved house and your old number is from a different area code, ask the gaining provider to confirm the port is feasible before placing the order.
Non-geographic numbers (08, 09, 03): Most residential customers do not have non-geographic numbers, but if you have a memorable 08 or 03 number tied to a business or charity use, the porting rules differ slightly. Confirm with both losing and gaining providers before switching.
Voicemail history and call records: These do NOT port. Your existing voicemail history with the losing provider, your call history, and any saved contacts on a previous landline phone are not transferred to the new provider. Note voicemail PINs and any important call records before switching.
Number block ports: If you have multiple numbers on a single account (rare for residential customers, more common for small businesses or shared accommodations), the gaining provider needs to handle a "number block port" which has slightly different timing. Confirm at sign-up.
Ex-directory and silent numbers: These settings do NOT automatically transfer with the port. After your number ports, contact the new provider to re-confirm any ex-directory or silent number preferences.
To keep your existing number when switching, the practical steps are: (1) Provide your existing landline number at sign-up with the new provider so the porting can be initiated correctly. (2) Confirm the porting is included in your Switching Information Notification when it arrives within 1-5 working days. (3) On activation day, expect the number to begin routing through the new service; some providers complete the port a day or two after broadband activation rather than simultaneously, so brief periods where calls may be temporarily routed through the old service are normal. (4) After activation, test by making and receiving calls to confirm everything is working. (5) If anything is incorrect, contact the gaining provider to investigate; the number portability framework includes specific dispute-resolution processes if a port is mishandled.
Honest take: The number portability framework is one of the longer-running and most reliable bits of UK telecoms regulation. In our experience the overwhelming majority of UK 2026 broadband switches preserve the existing landline number without any visible issue. The cases where things go wrong tend to involve unusual circumstances (very old numbers from areas that have been re-organised, ported numbers being ported again, old "shared" numbers from co-tenanted properties) and are typically resolvable within 1-2 weeks once flagged. Don't let "what happens to my number" be a barrier to switching - it almost always works.
How number porting works under One Touch Switch
Under One Touch Switch (OTS), introduced 12 September 2024, number porting and broadband cancellation are coordinated by the gaining provider via the central TOTSCo Hub messaging platform. You don't manage the port separately; it happens as part of the OTS workflow with the same 1-5 working day Switching Information Notification window and 10-14 working day overall switching timeline.
1. Order placement: When you place the order with the new provider, you provide your existing landline number along with your address and current provider name. The gaining provider's system passes this information into the OTS Match Request via the TOTSCo Hub.
2. Match Response includes number portability information: The losing provider's Match Response (within 60 seconds electronically) confirms your identity at the address and includes the technical details needed to coordinate the number port alongside the broadband switch.
3. Switching Information Notification states the port: Within 1-5 working days you receive the Switching Information Notification from the gaining provider; this confirms the activation date and the fact that your number is being ported as part of the switch. If the SIN does NOT mention the port, contact the gaining provider before consenting - this could indicate a porting issue that needs resolving.
4. Number activates with new service: On activation day the broadband and Digital Voice service goes live with your existing number; calls to your number begin routing through the new provider's network. In some cases the number port completes a day or two after the broadband activation rather than simultaneously - the gaining provider's customer service can confirm timing for your specific switch.
5. Old service disconnected: Under OTS the losing provider disconnects the old broadband and PSTN landline service on the same day the new service activates. No notice charges apply beyond the activation date.
Number porting under OTS does not require any additional customer action beyond providing your existing number at sign-up. The legacy NoT+ process used before September 2024 sometimes required customers to coordinate porting separately with both providers; OTS eliminates this complexity by integrating number portability into the gaining-provider-led switching workflow. This is one of the lesser-known practical improvements OTS has delivered alongside the more visible benefits like ending notice charges and parallel running.
The PSTN switch-off and what it means for your number
The Public Switched Telephone Network (PSTN) is the analogue, copper-wire-based legacy phone network that has carried UK landline calls since the 19th century. It is being switched off entirely by 31 January 2027, replaced by digital IP-based voice services delivered over your broadband connection. This is one of the most significant UK telecoms infrastructure changes in decades and affects every UK landline customer regardless of whether they're switching broadband providers or staying put.
Original target: 31 December 2025 - the industry's original PSTN switch-off date.
First pause (March 2022): BT paused its Digital Voice rollout for over a year, partly because lengthy power cuts during winter 2021/22 brought the power-cut resilience issue "into sharper focus".
Second pause and timeline revision: Migration was paused twice in response to concerns raised about the impact on customers who rely on landlines or telecare devices. The deadline was pushed back to address vulnerable customer protections.
Stop-sell of new PSTN lines: Openreach stopped selling new PSTN and ISDN lines on 5 September 2023. All new orders since then have been delivered on digital infrastructure.
Active migration phase 2024-2026: Major providers actively migrating customers, often when customers switch broadband providers or upgrade to full fibre. By July 2024 there were 5.2 million UK customers still on PSTN; by July 2025 this had fallen to 3.2 million.
Final hard deadline: 31 January 2027. Per Openreach (as cited in House of Commons Library briefing April 2026), this date is now "locked in" - the technical barriers to migration have been resolved and the deadline will not move again. All remaining PSTN connections will be terminated on this date.
Legacy line price increases: Openreach has confirmed staged wholesale price rises on legacy copper line rentals during 2026: approximately +20 percent from April, +40 percent from July, and another +40 percent from October. This roughly doubles the annual cost for businesses or households still on legacy lines by autumn 2026 - a deliberate cost incentive to accelerate migration.
Emergency Voice Access (EVAC): Lines left on the old platform at switch-off may fall back to Emergency Voice Access, which supports emergency calls only and does not carry broadband or device signalling. This is the absolute fallback; in practice every active customer is expected to have migrated to a full digital service before the deadline.
For someone switching broadband providers in 2026, the PSTN switch-off context matters because virtually every new UK broadband contract from any major provider now includes Digital Voice rather than analogue landline. If you're switching from a provider where you still have an analogue PSTN landline (less likely as we approach 2027 but still possible for some customers), the broadband switch will also bring a Digital Voice migration. Your number is preserved through both transitions; the underlying technology delivering calls to that number changes from copper PSTN to digital IP-based service.
Honest take: The PSTN switch-off is genuinely the largest UK telecoms infrastructure change since analogue television was retired in 2012. Given the universal nature of UK landlines (most UK households have had one for decades), the relatively limited public awareness of the upcoming change has been a recurring concern from charities, telecare providers, and consumer groups. If you have elderly relatives, neighbours, or anyone you know who relies on a landline, this is worth raising with them ahead of their migration - particularly the implications for telecare devices and power-cut resilience.
Digital Voice explained: BT, Sky, Virgin Media branded variants
"Digital Voice" is BT's branding for Voice over Internet Protocol (VoIP) phone service delivered over your home broadband connection rather than a separate copper landline. Other providers use different branded names but the underlying technology is essentially the same: phone calls are converted into data packets and routed over your broadband connection rather than a dedicated voice circuit. In day-to-day use, Digital Voice is functionally indistinguishable from a traditional landline phone service - calls work the same way, your number is preserved, and call quality is typically equal to or better than the legacy PSTN.
BT Digital Voice: The most widely-known Digital Voice brand, launched by BT in 2021 and progressively rolled out to BT customers since. Works with the BT Smart Hub 2 router; existing analogue handsets plug into the back of the router via a phone-port socket. BT had migrated over 2 million customers to Digital Voice by 2026 per Which? coverage.
Sky Voice (Sky Talk Internet Calls): Sky's Digital Voice service for Sky Full Fibre customers. If you sign up to Sky Full Fibre, your Sky Talk package automatically includes Internet Calls. Sky Broadband 75 customers also receive this on Full Fibre.
Virgin Media Voice: Virgin Media's Digital Voice service for Virgin Media customers. Operates over Virgin Media's cable and Nexfibre full fibre networks.
TalkTalk Digital Voice: TalkTalk's Digital Voice service for TalkTalk Future Fibre and other digital broadband customers.
Vodafone digital phone service: Vodafone's Digital Voice equivalent for Vodafone broadband customers. Operates across Openreach and CityFibre footprints.
EE digital home phone: EE Group provides Digital Voice for EE-branded broadband customers (EE is now part of BT Group, sharing technology with BT Digital Voice).
Plusnet Digital Voice: Plusnet's Digital Voice service (also part of BT Group).
NOW Broadband: NOW Broadband (Sky group) Digital Voice variant.
Altnet Digital Voice solutions: Smaller altnets (Hyperoptic, Community Fibre, toob, YouFibre on Netomnia, Cuckoo, Zen, etc.) provide Digital Voice via their own service or third-party VoIP providers. Some altnets offer broadband-only with no included landline; you can use a third-party VoIP service if you want to keep a phone number.
From a customer perspective, the practical difference between Digital Voice and the legacy PSTN landline is in how the phone connects: traditional analogue phones plug into the back of your broadband router (or a special adapter) rather than a separate phone socket on the wall. When the router is powered off (during a power cut) or your broadband is down, Digital Voice calls cannot be made - which is the core reason for the Ofcom power-cut resilience requirement covered in the next section. Call quality is typically equal to or better than the legacy PSTN; sound quality is at least as good as a mobile phone and often better than a traditional landline.
Setting up Digital Voice when you switch broadband is typically straightforward: most major providers ship a router with a phone-port socket on the back; you plug your existing analogue phone into this socket; the phone works as normal once the broadband is active. Some customers may want to use cordless DECT phones that connect wirelessly to a base station plugged into the router; these work with Digital Voice the same way they did with the legacy PSTN.
Power-cut protection and battery backup requirements
The single most important practical difference between traditional analogue PSTN landlines and digital IP-based Digital Voice is power-cut behaviour. Traditional analogue landlines drew their small operating power from the phone exchange itself, so they continued to work during local power cuts at customer premises (assuming the wider network and exchange remained powered). Digital Voice phones run through your broadband router which requires mains electricity at your home; when the power goes out, Digital Voice calls cannot be made unless there is a battery backup.
Ofcom recognised this resilience gap and requires UK phone providers to take measures to ensure uninterrupted access to emergency services for at least 1 hour during a power cut. In practice this means: providing a battery backup unit (BBU) for the router, free of charge for vulnerable customers; offering a BBU on a voluntary or paid basis for other customers who request one; or providing an alternative such as a mobile phone for customers who would prefer that solution.
Battery backup unit (BBU): A small battery pack that connects to your broadband router and provides 1+ hours of operation during a power cut, supporting emergency calls. Major providers including BT, Sky, Virgin Media, TalkTalk, and Vodafone offer BBUs to customers who need or request them. Free for vulnerable customers (see vulnerable customer section below); voluntary or modest paid for other customers.
Mobile phone alternative: For customers who don't want a BBU, having a charged mobile phone with sufficient battery is an acceptable alternative for emergency-call access during power cuts. Providers may ask whether you have a mobile phone available before issuing a BBU; if you confirm you do, the BBU may not be provided automatically.
UPS (uninterruptible power supply) for whole-router operation: Some customers (particularly home workers, small business operators in residential premises, or anyone who depends on continuous broadband during outages) opt for a small UPS that powers the router and ONT (optical network terminal for FTTP) for several hours during a power cut. This provides full Digital Voice plus broadband during the outage rather than just emergency-call access.
Cordless phone considerations: Cordless DECT phones with bases plugged into the router need their own power supply for the base station. During a power cut, even with a router BBU in place, a cordless phone base without its own power will not work. A simple corded analogue phone plugged directly into the router's phone-port socket is the most reliable option for emergency calls.
The practical implications for customers in 2026 are: most households will receive their Digital Voice service over a router that does not include a built-in battery backup, on the assumption that mobile phone availability provides the emergency-call alternative. If you do not have reliable mobile reception at your home (which is common in rural areas, basement flats, or properties with thick walls), or if you have any reason to need landline-based emergency access during power cuts, request a BBU from your provider when you sign up or migrate. Vulnerable customers should always be offered a BBU as part of the standard migration; if you or someone you know hasn't been, request one explicitly.
Honest take: The 1-hour BBU requirement is a regulatory minimum rather than an engineering target. In practice, longer power cuts (4+ hours, which do happen during winter storms) will exceed BBU capacity and leave even BBU-equipped customers without phone service unless they have a mobile alternative. For genuinely critical landline-dependent situations (someone with serious health conditions, telecare equipment, fire alarm systems with PSTN diallers), the better solution is a multi-hour UPS for the router rather than just a 1-hour BBU. This is an area where customer expectations and the regulatory minimum don't always align; ask your provider explicitly what duration their BBU provides if you have any concerns.
Vulnerable customer protections during the transition
The PSTN switch-off pause through 2022-2024 was driven primarily by concerns about the impact on vulnerable customers, including elderly customers who depend on landlines, customers with telecare or pendant alarms, customers with serious medical conditions monitored remotely, and customers in rural areas without reliable mobile alternatives. Ofcom and the major UK providers have built specific protections into the migration framework to address these concerns; understanding these protections is important if you or someone you know falls into a vulnerable customer category.
Free battery backup unit (BBU): Vulnerable customers should receive a BBU at no charge as part of the standard migration to Digital Voice. This applies to customers who depend on their landline for telecare, medical alerts, or who have no mobile phone alternative.
Pre-migration contact and consent: BT customers should be contacted at least 4 weeks in advance before migration to Digital Voice, with explicit advance notice of the date and the changes that will occur.
Right to refuse migration in certain circumstances: Customers who do not want to migrate to Digital Voice have the right to refuse in some cases. For BT customers specifically, calling BT within 7 days of receiving the migration letter allows the customer to be moved onto a Broadband Only plan instead, retaining their existing analogue landline service for as long as the wider PSTN network supports it (which is until January 2027 at the latest).
Telecare register: Major UK providers maintain telecare registers identifying customers with telecare devices that may need attention during migration. If you or a family member has a telecare device (fall alarms, pendant alarms, medical monitoring devices), confirm with your provider that the device is on the register and that compatibility with the new Digital Voice service has been verified.
Coordination with telecare service providers: Some telecare service providers (Tunstall, Doro, Vital Connection, regional council telecare schemes) work directly with broadband providers to coordinate device upgrades or replacements during the migration. Contact your telecare provider as well as your broadband provider to confirm what's needed.
Citizens Advice and consumer support: Citizens Advice provides free, impartial advice on the Digital Voice migration including escalation paths if a vulnerable customer is being migrated without appropriate support. Available at citizensadvice.org.uk.
For customers helping elderly relatives, neighbours, or anyone vulnerable through the migration: the most important practical step is to ensure the customer's vulnerability status is known to their provider. Major UK providers maintain Priority Services Registers (or similar) that flag vulnerable customers for enhanced support; if your relative isn't on one, contact their provider to add them. This typically requires 5-10 minutes by phone and ensures proper protections including BBU provision, advance migration notice, and dedicated customer service support.
Telecare devices, alarms, and connected equipment
Many UK households have devices connected to the phone line that customers don't actively think about: telecare pendant alarms and fall alarms; intruder alarms with PSTN diallers; fire alarm monitoring systems; lift emergency phones (for buildings with lifts); door entry systems; PDQ card terminals on fallback lines; franking machines; and various other industrial control systems. Many of these devices were designed to use the analogue PSTN and may not work correctly with Digital Voice without an upgrade or replacement.
Telecare pendant alarms and fall alarms: Older units designed for analogue PSTN may not work reliably with Digital Voice. Modern telecare devices use 4G, IP, or specifically-tested Digital Voice compatibility. Contact your telecare service provider (Tunstall, Doro, Vital Connection, council schemes) before migration to confirm device compatibility or arrange replacement.
Intruder and fire alarms with PSTN diallers: These devices "phone" a monitoring centre when triggered. PSTN diallers will stop working at the January 2027 switch-off; many should be upgraded with a 4G or IP communications module before then. Contact your alarm maintenance company; do not wait until late 2026 when engineers will be very busy.
Lift emergency phones: Building lift emergency phones typically use PSTN. These need migration to digital alternatives; the lift maintenance company is responsible for arranging this. Building owners and managing agents should audit their lift emergency phone lines well before January 2027.
Door entry systems: Older door entry systems for blocks of flats sometimes use PSTN to route calls between the entry panel and individual flats. Modern systems use IP or wireless instead. Block managers should audit and upgrade as needed.
PDQ card terminals on fallback lines: Many UK businesses have PDQ payment terminals with a fallback PSTN line as backup. These need migration to all-IP solutions or 4G fallback.
Franking machines: Franking machines that connect to the postal service for credit reloading sometimes use PSTN. These need either replacement or alternative connectivity.
Fax machines: Most UK offices have moved away from fax, but some businesses (particularly in legal, medical, and government sectors) still have analogue fax machines. These can sometimes work over Digital Voice but reliability varies; consider whether the fax can be replaced with email-based alternatives.
For residential customers, the practical telecare audit takes about 15 minutes: walk around your home and identify every device that has either a phone cable plugging into a wall socket or a base station that previously plugged into a phone line. Common items: pendant alarm bases (often charged from a power socket but with a phone connection), home security alarm panels, smart-home hubs that may have phone-line backup, kitchen burglar alarm panels. For each device, contact the device service provider to confirm Digital Voice compatibility or arrange a replacement. Most UK telecare service providers have been actively working through their customer base to upgrade older devices ahead of the January 2027 deadline; don't assume your device is up to date - confirm explicitly.
Honest take: The "things connected to the phone line that you don't think about" issue is genuinely the largest practical challenge of the PSTN switch-off, and the source of most of the past pause-and-restart cycles in the industry timeline. In our experience, residential customers underestimate how many devices in a typical UK home connect to the phone line until they actually look. The 15-minute audit is worth doing well before any migration, not just for safety but because device replacements during the actual migration window can be slow with engineers in high demand.
What if you don't want a landline anymore?
Many UK customers in 2026 don't actively use their landline for outgoing calls and could happily live without one. Trends data shows declining UK landline usage as mobile phones have become primary communication devices for most households. However, the question of whether you can or should drop your landline as part of switching broadband has some specific considerations in 2026.
Most UK altnets: Hyperoptic, Community Fibre, toob, YouFibre on Netomnia, Cuckoo, Zen, Brsk, Trooli, and most other altnets offer broadband-only packages without an included landline. Customers can simply not use the phone-port socket on the router.
Major UK ISPs broadband-only: BT, Sky, Virgin Media, TalkTalk, Vodafone, EE, Plusnet, NOW Broadband all offer broadband-only packages. Some still require a phone line technically (because of underlying SoGEA technology that uses the phone-line copper without active voice service) but you don't need to use the phone service or pay for calls.
Pricing implications: Dropping the phone service from a bundled broadband-plus-phone package may save £2-£5 per month on the broadband element. However, if you've ported your number from a previous provider's bundled package and now want to drop the phone, you may lose your existing number unless you arrange to port it to a third-party VoIP service first (see below).
Number preservation if dropping landline: If you don't want a landline at the new broadband provider but want to keep your existing UK number for future use, you can port the number to a third-party VoIP service like Skype, Vonage, magicJack, sipgate, or various UK-specific VoIP providers. These typically cost £2-£5 per month and let you keep the number active without committing to a full landline service.
The practical decision-tree for someone considering whether to drop their landline at the next switch: (1) Do you actually use the number for incoming calls? If yes, keep it. (2) Do family members, businesses, or organisations contact you on the number? If yes, consider keeping it for at least the next 12 months while you transition to mobile-only. (3) Have you had the number for many years and feel attached to it? Reasonable; consider porting to a low-cost third-party VoIP service to preserve future flexibility. (4) Are you happy to lose the number permanently? In that case dropping the landline at the broadband switch and not arranging porting is straightforward.
Honest take: A surprising number of UK households continue to pay for landline services they barely use, mostly because the bundled broadband-plus-phone package was the standard offering when they last signed up. In 2026, broadband-only is genuinely standard across most UK providers, and explicitly choosing broadband-only at the next switch can save £24-£60 per year while not affecting any service most customers actually use. If you're unsure, look at your phone bill from the last 6 months and count actual outgoing calls - many UK households make zero or single-digit calls per year despite paying for the line.
Mobile number portability via PAC code (separate process)
UK mobile numbers can also be ported between providers but use a different process called PAC (Porting Authorisation Code). This is separate from the broadband number portability framework and applies to mobile-only switches. However, some 5G home broadband services use mobile network technology, which can blur the lines between fixed and mobile number portability in specific scenarios.
What a PAC is: Porting Authorisation Code - a 9-character alphanumeric code that authorises your mobile number to be moved from one mobile network to another. Issued free of charge by your existing mobile network within minutes of request.
How to get a PAC: Text PAC to 65075 from your existing mobile. The network must respond within 60 seconds with your PAC code (Ofcom rule). Alternatively call the existing network's customer service or use the online portal.
How to use a PAC: Provide the PAC to your new mobile network when signing up. The new network handles the port; the old service is cancelled automatically when the port completes (typically within 1 working day for most UK mobile ports).
PAC validity: PAC codes are valid for 30 days from issue. If you don't use the PAC within 30 days you'll need to request a new one.
5G home broadband considerations: If you have 5G home broadband (Three 5G Home Broadband, EE 5G Home Broadband, Vodafone 5G Home Broadband, O2 5G Home Broadband), the device uses a SIM which has a mobile number assigned to it. However, this number is typically a "data" number rather than a voice number and isn't normally used for calls. When switching between 5G home broadband providers, the SIM and number aren't typically ported - you receive a new device with a new SIM.
For most UK households in 2026 the mobile and fixed-line number worlds are entirely separate. You can have a UK landline number ported between broadband providers (the topic of this guide) and a UK mobile number ported between mobile networks (using PAC) at the same time without any conflict. The two processes use different regulatory frameworks but both are well-established and reliable.
What happens if you cancel without switching?
If you cancel your broadband contract without switching to a new provider (for example because you're moving to a property where another service is already active, or because you no longer want broadband at all), the question of what happens to your phone number depends on whether you take any action to preserve it.
Default outcome (no action taken): Your number is returned to the network operator's pool and may eventually be reassigned to another customer (typically after a 6+ month "quarantine" period). You permanently lose the number.
Port to a VoIP provider before cancellation: Request the new VoIP provider port your number from the existing landline provider before you cancel the broadband. This typically costs £2-£5 per month for the ongoing VoIP service but preserves your number indefinitely. Common UK options: Skype, Vonage, magicJack, sipgate, Voipfone.
Port to a mobile via mobile-network conversion service: Some mobile networks accept landline numbers via specific porting arrangements. This is less common and not all UK mobile networks support it; the result is your existing UK landline number ringing your mobile phone.
Coordinate with subsequent broadband activation: If there will be a gap between cancelling the existing broadband and activating new broadband at a new property, ensure the number portability is coordinated to bridge the gap. Most porting frameworks support this with sufficient advance notice but it's worth confirming with both the losing and gaining providers.
For someone simply moving house and not requiring broadband at the new property (for example moving into a property with a flatmate who already has broadband, or moving to a serviced apartment with included broadband), the realistic options for the number are: keep it via a VoIP provider for £2-£5 per month; or accept that you'll lose it and provide your mobile number going forward. The decision usually comes down to how attached you are to the specific number and whether anyone you don't want to lose contact with might call it without knowing your mobile.
2026 migration timeline: when will your number move?
The PSTN switch-off is happening at different speeds for different customer groups based on a combination of provider strategy, exchange-area readiness, and customer-specific factors like vulnerability registers and telecare device coordination. Understanding where your specific account sits in the migration timeline helps you plan ahead.
New broadband customers (any 2024-2026 sign-up): Already on Digital Voice from day one. Openreach stop-sell of new PSTN lines from September 2023 means all new orders since then have been delivered on digital infrastructure.
Existing customers who switch broadband providers in 2026: Migration to Digital Voice happens automatically as part of the switch. The new provider activates your service on Digital Voice; your number ports across.
Existing customers staying with current provider on legacy PSTN: Migration is happening progressively through 2026 with provider-led contact at least 4 weeks before migration. By July 2025 the population of UK PSTN customers had fallen from 5.2 million to 3.2 million; the remaining population is migrating progressively through 2026.
Vulnerable customers and telecare users: Provider migration teams typically coordinate with telecare service providers to ensure compatibility before migrating these customers. Migration may happen later in the timeline to allow device upgrades to complete first.
Customers in exchange areas with active migration: Migration can happen sooner than the customer would otherwise expect if the local exchange is being decommissioned. Openreach's published schedule shows several hundred exchange areas in active migration by September 2025, with full national coverage by late 2026.
Customers refusing migration (BT specific): BT customers calling within 7 days of receiving the migration letter can be moved onto a Broadband Only plan, retaining analogue landline until forced migration before January 2027.
Hard final deadline: 31 January 2027. All remaining PSTN connections terminated on this date. Lines left active on the legacy platform may fall back to Emergency Voice Access (emergency calls only).
For most UK customers in 2026 the migration to Digital Voice will happen either through their next broadband switch (if they're switching during 2026) or through their existing provider's progressive migration programme (if they're staying put). The advance notice period of 4+ weeks gives time to address device compatibility, BBU provision, and any other practical considerations. Customers who want to control the timing of their migration can switch broadband to a Digital Voice provider proactively rather than waiting for forced migration.
Free help and authoritative number portability sources
Independent third-party tools and authoritative regulatory sources to verify your number portability rights and understand the Digital Voice transition.
- Ofcom landline switching guidance: Authoritative regulatory guidance on number portability, the Public Switched Telephone Network (PSTN) migration, and the future of landline calls. Available at ofcom.org.uk/phones-and-broadband. Ofcom maintains specific consumer-focused pages on the digital landline upgrade.
- House of Commons Library briefing on the switch to digital landlines: Comprehensive parliamentary research briefing covering the PSTN switch-off timeline, government position, and protections for vulnerable customers. Available at commonslibrary.parliament.uk; latest version published April 2026.
- Citizens Advice: Free advice on consumer broadband and landline rights, including help with disputes, vulnerable customer protections, and complaints escalation related to Digital Voice migration. Available at citizensadvice.org.uk.
- Communications Ombudsman: Free, independent, government-approved ombudsman scheme for broadband and landline complaints from customers of providers signed up to the Communications Ombudsman scheme. Available at commsombudsman.org.
- CISAS: Free, independent, government-approved ombudsman scheme for broadband and landline complaints from customers of providers signed up to CISAS rather than Communications Ombudsman. Available at cisas.org.uk.
- BroadbandSwitch.uk postcode comparison: Multi-provider comparison across all major UK communications providers covering Openreach, Virgin Media plus Nexfibre, CityFibre retail brands, Hyperoptic, YouFibre on Netomnia, plus 4G and 5G home broadband options. All packages clearly identify whether Digital Voice is included.
- BroadbandSwitch.uk switching hub: Comprehensive UK 2026 switching reference covering OTS plus the wider Ofcom regulatory framework. Available at broadbandswitch.uk/switching-hub.html.
- BroadbandSwitch.uk One Touch Switch deep-dive: Detailed guide covering how OTS works including the integrated number portability framework. Available at broadbandswitch.uk/one-touch-switch-uk.html.
- BroadbandSwitch.uk step-by-step walkthrough: Action-oriented eight-step UK 2026 broadband switching walkthrough covering activation day, return of equipment, and verification. Available at broadbandswitch.uk/switch-broadband-uk.html.
- BroadbandSwitch.uk switching checklist: Printable, scannable checklist covering everything you need to do before, during, and after a switch. Available at broadbandswitch.uk/broadband-switch-checklist.html.
- BT Digital Voice information: BT's customer-facing Digital Voice migration information including BBU provision and vulnerable customer protections. Available at bt.com/digitalvoice.
- Sky Voice and Sky Talk information: Sky's customer-facing information on Sky Voice (Internet Calls) for Sky Full Fibre and broadband customers. Available via Sky Help Centre.
- Virgin Media Voice information: Virgin Media's customer-facing information on Virgin Media Voice for cable and Nexfibre customers.
- Telecare Services Association (TSA): Trade association for UK telecare service providers; useful resource for verifying telecare device compatibility with Digital Voice. Available at tsa-voice.org.uk.
- Which? Digital Voice guide: Independent consumer organisation Which? maintains a comprehensive Digital Voice guide updated regularly; Yvette Caster (Which? telecoms champion) provides ongoing coverage. Available at which.co.uk.
How we put this guide together
This UK 2026 broadband number portability and Digital Voice guide draws on Ofcom's General Conditions of Entitlement, particularly C7.18-C7.27 (switching obligations including OTS) and the longstanding number portability framework dating from 1996; Ofcom's published guidance on the digital landline upgrade including the 1-hour minimum power-cut emergency-services battery backup requirement; the House of Commons Library research briefing CBP-9471 on the switch to digital landlines published April 2026 by Adam Clark, including the documented fall in UK PSTN customers from 5.2 million in July 2024 to 3.2 million in July 2025; Openreach's confirmation that the 31 January 2027 PSTN switch-off date is "locked in" with technical barriers to migration resolved; Openreach's published staged wholesale price rises on legacy copper line rentals during 2026 (~+20 percent April, +40 percent July, +40 percent October); BT Business and BT consumer information on the PSTN switch-off, BT Digital Voice, and the BT migration programme that has moved over 2 million customers to Digital Voice; Sky's customer-facing information on Sky Voice and Internet Calls for Sky Full Fibre packages; Virgin Media's customer-facing information on Virgin Media Voice for cable and Nexfibre customers; Which?'s Digital Voice and landline phone switch-off coverage by Yvette Caster updated March 2026 covering provider branding, vulnerable customer protections, and the right to refuse migration; broadband.co.uk's customer-facing Digital Voice guide covering BT's 7-day Broadband Only opt-out for customers refusing migration; Connection Technologies' VoIP Phone Guide 2026 for UK SMEs covering the PSTN switch-off business implications including alarm systems, lift emergency phones, and PDQ card terminal migration requirements; AMVIA's PSTN Switch-Off 2027 guide covering the September 2025 Openreach migration schedule with several hundred exchange areas in active migration; Modern Networks' BT PSTN switch-off 2027 guide covering Emergency Voice Access (EVAC) for lines left on the legacy platform at switch-off; HJS Technology's PSTN Switch Off 2026 final countdown guide; UK mobile number portability rules including the PAC (Porting Authorisation Code) text-65075 process within 60 seconds and 30-day PAC validity; Telecare Services Association (TSA) guidance on telecare device compatibility with Digital Voice; plus published 2026 Switching Information Notification examples from BT, Sky, Virgin Media, Vodafone, TalkTalk, EE, Plusnet, NOW Broadband, Zen Internet, toob, YouFibre on Netomnia, Cuckoo, Hyperoptic, Community Fibre, Brsk, Trooli, and Earth Broadband.
Editorial: Written by Adrian James, broadband editor. Reviewed by Dr Alex J. Martin-Smith, head of editorial. Last updated 28 April 2026; next review within 90 days. Corrections welcome via our corrections process.
How we earn: BroadbandSwitch.uk is independent. We sometimes earn affiliate fees from broadband switching deals, including some products mentioned in this guide; this never affects which providers we cover or how we describe them. See our affiliate disclosure and editorial policy.
Frequently asked questions about phone numbers and broadband switching
Will I keep my existing phone number when I switch broadband?
Yes, in almost all cases. Number portability is a protected UK consumer right under Ofcom regulation since 1996, and you can keep your existing UK landline number when switching to almost any other UK broadband provider. The new (gaining) provider handles the porting automatically as part of the One Touch Switch (OTS) process via the central TOTSCo Hub messaging platform; you don't need to take any special action beyond providing your existing number at sign-up. Number porting typically takes 10-15 working days alongside the broadband activation, with the visible customer experience being that your number simply continues to work with the new provider. Some edge cases may have constraints: geographic numbers tied to specific exchange areas (the leading "01" or "02" digits indicate area) work without issue at the same address but may require confirmation if you've moved to a different area code; non-geographic numbers (08, 09, 03) have slightly different rules and are worth confirming before switching; ex-directory and silent number settings do NOT automatically transfer with the port and need to be re-confirmed with the new provider; voicemail history, call records, and saved contacts on a phone do NOT port and should be noted before switching. In our experience the overwhelming majority of UK 2026 broadband switches preserve the existing landline number without any visible issue.
What is Digital Voice and do I have to use it?
"Digital Voice" is BT's branding for Voice over Internet Protocol (VoIP) phone service delivered over your home broadband connection rather than a separate copper landline. Other providers use different branded names: Sky Voice (sometimes called Sky Talk Internet Calls), Virgin Media Voice, TalkTalk Digital Voice, Vodafone digital phone service, EE digital home phone. All of these are essentially the same technology - phone calls are converted into data packets and routed over your broadband connection rather than a dedicated voice circuit. In day-to-day use Digital Voice is functionally indistinguishable from a traditional landline phone service - calls work the same way, your number is preserved, and call quality is typically equal to or better than the legacy PSTN. The transition to Digital Voice is happening for ALL UK landline customers as part of the wider PSTN switch-off, which has a confirmed hard deadline of 31 January 2027. In most cases customers will be migrated to Digital Voice automatically when they switch broadband providers, upgrade to full fibre, or when their existing provider's progressive migration programme reaches them (with at least 4 weeks advance notice). BT customers calling within 7 days of receiving the migration letter can be moved onto a Broadband Only plan to retain analogue landline temporarily; this option becomes unavailable as the wider PSTN switches off. After 31 January 2027, Digital Voice (or VoIP through a third-party provider) is the only landline phone option available; analogue PSTN is no longer available regardless of customer preference.
What happens to my phone number during a power cut on Digital Voice?
Digital Voice phones run through your broadband router, which requires mains electricity. When the power goes out at your home, Digital Voice calls cannot be made unless there is a battery backup. Ofcom requires UK phone providers to take measures to ensure uninterrupted access to emergency services for at least 1 hour during a power cut. In practice this typically means: (1) Battery backup unit (BBU) - a small battery pack that connects to your broadband router and provides 1+ hours of operation during a power cut. Major UK providers offer BBUs free of charge for vulnerable customers; voluntary or modest paid for other customers. (2) Mobile phone alternative - for customers who don't want a BBU, having a charged mobile phone with sufficient battery is an acceptable alternative for emergency-call access. Providers may ask whether you have a mobile phone before issuing a BBU. (3) UPS (uninterruptible power supply) for full-router operation - some customers opt for a small UPS that powers the router and ONT (optical network terminal for FTTP) for several hours during a power cut, providing full Digital Voice plus broadband during the outage rather than just emergency-call access. Cordless DECT phones with bases plugged into the router need their own power supply for the base station; during a power cut, even with a router BBU in place, a cordless phone base without its own power will not work - a simple corded analogue phone plugged directly into the router is the most reliable option for emergency calls. If you don't have reliable mobile reception at your home (common in rural areas, basement flats, properties with thick walls), or if you have any reason to need landline-based emergency access during power cuts, request a BBU from your provider explicitly.
When is the PSTN switch-off and what does it mean for my number?
The PSTN switch-off is "locked in" for 31 January 2027 according to Openreach (as cited in House of Commons Library briefing April 2026). This is a hard deadline; there is no extension, no fallback, and no grace period. By July 2025 the number of UK landline customers on the legacy PSTN had fallen from 5.2 million (July 2024 baseline) to 3.2 million; the remaining customers are migrating progressively through 2026. For your phone number specifically: number portability is preserved through the PSTN switch-off transition. You keep your existing UK landline number; what changes is the technology delivering calls to that number, transitioning from analogue copper PSTN to digital IP-based Digital Voice over your broadband connection. The migration timeline depends on which customer category you fall into: new broadband customers from September 2023 onwards are already on Digital Voice (Openreach stop-sell of new PSTN lines from that date); existing customers who switch broadband providers in 2026 are migrated automatically as part of the switch; existing customers staying with their current provider are migrated progressively through 2026 with at least 4 weeks advance notice; vulnerable customers and telecare users are typically coordinated with telecare service providers to ensure compatibility before migration; customers in exchange areas with active migration may be migrated sooner if the local exchange is being decommissioned. Openreach has confirmed staged wholesale price rises on legacy copper line rentals during 2026 (~+20 percent April, +40 percent July, +40 percent October) - a deliberate cost incentive to accelerate migration.
What devices in my home connect to the phone line and might need attention?
Many UK households have devices connected to the phone line that customers don't actively think about. The 15-minute home audit before any migration is the most useful single step: walk around your home and identify every device that has either a phone cable plugging into a wall socket or a base station that previously plugged into a phone line. Common UK landline-connected devices that may need attention before the January 2027 PSTN switch-off: (1) Telecare pendant alarms and fall alarms - older units designed for analogue PSTN may not work reliably with Digital Voice; modern devices use 4G, IP, or specifically-tested Digital Voice compatibility. (2) Intruder and fire alarms with PSTN diallers - these will stop working at the January 2027 switch-off; many should be upgraded with a 4G or IP communications module before then. (3) Lift emergency phones in buildings with lifts - typically use PSTN; building owners and lift maintenance companies should arrange migration well before the deadline. (4) Door entry systems for blocks of flats - older systems sometimes use PSTN; modern systems use IP or wireless. (5) PDQ card terminals on fallback lines - many UK businesses have payment terminals with a fallback PSTN line as backup; need migration to all-IP or 4G fallback. (6) Franking machines, fax machines, and various smart-home hubs that may have phone-line backup. For each device, contact the device service provider (telecare service like Tunstall, alarm maintenance company, lift maintenance company, etc.) to confirm Digital Voice compatibility or arrange a replacement. Don't wait until late 2026 when engineers will be in very high demand.
Are there special protections for vulnerable customers during the migration?
Yes, vulnerable customers receive enhanced protections during the Digital Voice migration as a result of the regulatory pause-and-restart cycles through 2022-2024 that addressed concerns about impact on customers who depend on landlines. Key protections in 2026: (1) Free battery backup unit (BBU) - vulnerable customers should receive a BBU at no charge as part of the standard migration to Digital Voice. This applies to customers who depend on their landline for telecare, medical alerts, or who have no mobile phone alternative. (2) Pre-migration contact and consent - BT customers should be contacted at least 4 weeks in advance before migration with explicit advance notice of the date and changes. (3) Right to refuse migration in certain circumstances - BT customers calling within 7 days of receiving the migration letter can be moved onto a Broadband Only plan instead, retaining analogue landline service for as long as the wider PSTN supports it. (4) Telecare register - major UK providers maintain telecare registers identifying customers with telecare devices that may need attention during migration. Contact your provider to confirm telecare devices are on the register and Digital Voice compatibility has been verified. (5) Coordination with telecare service providers - Tunstall, Doro, Vital Connection, regional council telecare schemes work directly with broadband providers to coordinate device upgrades during migration. (6) Citizens Advice support - free, impartial advice on the Digital Voice migration including escalation paths if a vulnerable customer is being migrated without appropriate support. For customers helping elderly relatives, neighbours, or anyone vulnerable through the migration, the most important step is to ensure the customer's vulnerability status is known to their provider via the Priority Services Register; this typically requires 5-10 minutes by phone and ensures proper protections.
Can I keep my number if I cancel broadband without switching?
By default, no - if you cancel broadband without switching to a new provider, your phone number is returned to the network operator's pool and may eventually be reassigned to another customer (typically after a 6+ month "quarantine" period). You permanently lose the number unless you take specific action to preserve it. To keep your existing UK number when cancelling broadband: (1) Port to a third-party VoIP provider before cancellation - request the new VoIP provider port your number from the existing landline provider before you cancel the broadband. This typically costs £2-£5 per month for ongoing VoIP service but preserves your number indefinitely. Common UK options include Skype, Vonage, magicJack, sipgate, Voipfone. (2) Port to a mobile via mobile-network conversion service - some mobile networks accept landline numbers via specific porting arrangements; less common and not all UK mobile networks support it; the result is your existing UK landline number ringing your mobile phone. (3) Coordinate with subsequent broadband activation - if there will be a gap between cancelling and activating new broadband at a different property, ensure the number portability is coordinated to bridge the gap. Most porting frameworks support this with sufficient advance notice. For someone simply moving house and not requiring broadband at the new property, the realistic options for the number are: keep it via a VoIP provider for £2-£5 per month; or accept the loss and provide your mobile number going forward. The decision usually comes down to how attached you are to the specific number and whether anyone might call it without knowing your mobile.
How is mobile number portability different from landline portability?
UK mobile numbers can be ported between providers but use a different process called PAC (Porting Authorisation Code) rather than the OTS-coordinated landline portability framework. This is separate from broadband number portability and applies to mobile-only switches. Practical mobile portability: (1) What a PAC is - a 9-character alphanumeric code that authorises your mobile number to be moved from one mobile network to another, issued free of charge by your existing mobile network within minutes of request. (2) How to get a PAC - text PAC to 65075 from your existing mobile. The network must respond within 60 seconds with your PAC code (Ofcom rule). Alternatively call existing network customer service or use the online portal. (3) How to use a PAC - provide the PAC to your new mobile network when signing up; the new network handles the port; the old service is cancelled automatically when the port completes (typically within 1 working day for most UK mobile ports). (4) PAC validity - 30 days from issue. If you don't use the PAC within 30 days you'll need to request a new one. (5) 5G home broadband considerations - if you have 5G home broadband (Three 5G Home Broadband, EE 5G Home Broadband, Vodafone 5G Home Broadband, O2 5G Home Broadband), the device uses a SIM with a mobile number assigned to it. However, this number is typically a "data" number rather than a voice number and isn't normally used for calls; switches between 5G home broadband providers don't typically port the SIM and number, you receive a new device with a new SIM. For most UK households the mobile and fixed-line number worlds are entirely separate and you can have a UK landline number ported between broadband providers and a UK mobile number ported between mobile networks at the same time without any conflict.
References
- Clark, A. (2026, April). The switch to digital landlines (Research Briefing CBP-9471). House of Commons Library, UK Parliament. https://commonslibrary.parliament.uk/research-briefings/cbp-9471/
- Caster, Y. (2026, March). Digital Voice and the landline phone switch-off: what it means for you. Which? https://www.which.co.uk/reviews/broadband/article/digital-voice-and-the-landline-phone-switch-off-what-it-means-for-you-aPSOH8k1i6Vv
- Connection Technologies. (2026, April). VoIP phone guide 2026: beat the 2027 PSTN switch-off. https://connection-technologies.co.uk/hosted-voice/voip-phone-2026-pstn-switch-off-guide