Ofcom enforcement and advice, October 2026 A phone company has been fined for failing to stop scammers misusing its numbers. Your part is simple: don't ring back, report to 7726 £437,500 fine for Tismi, after a 30% discount for admitting liability Ofcom, 21 Oct 2026 366,000 phone numbers, approximately, exposed to potential misuse for over two years Ofcom 7726 the free number for reporting scam calls and texts. It spells SPAM Ofcom Falling the number of people who say they've recently had a suspicious call, over the last four years Ofcom, 2 Oct 2026 On 21 October 2026, Ofcom fined telecoms provider Tismi £437,500. Ofcom found it didn't properly check the business customers it passed phone numbers to, or watch how those numbers were used, leaving about 366,000 numbers exposed to potential misuse, including by scammers, for over two years. The same day, Ofcom opened an investigation into another provider, Xtra Phones UK, where it has made no findings. For you, the advice is simple. If an unknown number rings once and hangs up, Ofcom says don't call it back. If you get a scam call, such as an automated "job offer", Ofcom says to "hang up, don't give out any personal details, and report the call to 7726". There's good news too. Ofcom says the number of people who say they've recently had a suspicious call has fallen over the last four years. An Ofcom spokesperson also says telecoms companies are blocking millions of scam calls every month. Key facts, checked 21 October 2026 Who this is for: Anyone who's had a missed call from a number they don't know, anyone looking out for an older relative, and anyone who wants to know what Ofcom's latest fine means in practice. For the wider picture, see our guide to broadband and telecoms scams. Direct answer: Because it didn't do enough to stop the phone numbers it handed out being misused. Ofcom found Tismi passed numbers to business customers without proper checks, didn't monitor how they were used and had no formal process for handling reports of misuse, between at least November 2022 and January 2025. Ofcom gives out phone numbers, usually in large blocks, to telecoms companies, which can pass them on to other businesses. Ofcom expects those companies to carry out "know your customer" checks on their business customers, to stop scammers getting valid numbers in the first place, and to keep watching for misuse. Ofcom found that Tismi BV, which it describes as part of Link Mobility, had no appropriate or proportionate measures in place, which exposed about 366,000 numbers to potential misuse "for over two years". The Tismi case, from first failing to fine The fine is £437,500, which includes a 30% discount on a penalty of £625,000 because Tismi admitted liability and settled. Ofcom says the penalty would have been significantly higher if Tismi hadn't co-operated and brought in new processes within a few months. The money goes to HM Treasury, and Tismi must also show Ofcom its new checks, monitoring and handling of misuse reports. "There's no excuse for communications providers failing to put in the proper checks and balances to prevent numbers being misused. Today we're sending a clear message to industry that any company that puts customers at the mercy of scammers will face the consequences." George Lusty, Ofcom's Director of Enforcement, 21 October 2026 Ofcom's full decision isn't public yet: it says a non-confidential version will be published later, to protect other investigations. You can read Ofcom's summary on its Tismi case page. Direct answer: One way is through the chain that hands numbers out. Ofcom gives numbers to telecoms providers, and they can pass them on to business customers. If a provider doesn't check who it's passing numbers to, or watch how they're used, scammers can end up with real, working UK numbers. How a real UK number can end up with a scammer Ofcom Gives out phone numbers, usually in large blocks Telecoms provider Can pass numbers on to business customers Business customer Uses the numbers, or should Your phone Where a misused number turns up The three safeguards Ofcom expects from providers, and where Ofcom found Tismi fell short Scammers can also fake the number that shows on your screen, which is called spoofing. Ofcom says spoofed calls can appear to come from a bank, HMRC, a delivery company or even Ofcom itself, so a familiar-looking number isn't proof a call is real. Ofcom published its good practice guide for providers on preventing misuse of sub-allocated numbers on 15 November 2022, the same date the period covered by Ofcom's finding against Tismi begins. Direct answer: It's a call that rings for under a second, so it shows as a missed call, in the hope you'll ring back. Ofcom says if you do, you can be connected to a premium-rate service and charged for as long as you stay on the line. It's sometimes called a Wangiri scam. How a missed-call scam works 1. It rings once The call lasts under a second, Ofcom says. 2. You see a missed call Automated systems call large numbers of phones. 3. You ring back This is the step the scammer is waiting for. 4. You're charged A call-back can connect you to a premium-rate service, charged while you stay on the line. Ofcom's other current warning is about job-offer calls: "an automated voice claiming to have a job offer for you". Both kinds of call are designed to get you to ring back the scammer's number. Once you're talking, Ofcom says, scammers may pressure you to share sensitive information or make a payment, and "You could also run up a large bill by unknowingly calling a premium-rate number". Direct answer: Ofcom says don't call back if you don't recognise the number, especially numbers beginning 070, 076, 084, 087, 090, 091 or 118, and unfamiliar international numbers. Missed a call from one of these? Don't ring back Ofcom has tackled this before, and it worked. After it capped what providers could charge for connecting calls to 070 numbers in October 2019, Ofcom reported that fraudulent calls using 070 numbers fell by 75% between October 2019 and September 2020, based on data from BICS (Ofcom, 2020). Direct answer: No. Ofcom says don't call back a number you don't recognise. If it's important, a genuine caller can leave a message, and you can always contact an organisation on a number you find yourself, from its official website or published number, rather than one given in a call or message. Should I call back? A 20-second check Yes You can call back, using the number saved in your contacts. No Don't ring back yet. Ask the next question. No Don't call back. If you think it was a scam, text the number to 7726 for free. Yes, from an organisation Don't use the number in the message. Contact the organisation using a number from its official website or published number. Direct answer: Text the caller's number to 7726, which is free and spells SPAM on a keypad. Ofcom says: "Open recent calls, select the number, then copy or share it in a text to 7726." A report alerts your mobile provider to investigate and potentially block the number. How to report to 7726, free A scam call on your mobile "Open recent calls, select the number, then copy or share it in a text to 7726." A scam text on an iPhone "Tap and hold on the message, tap More, then the forward arrow, and send to 7726." A scam text on Android "Tap and hold on the message, tap Forward, and send to 7726." WhatsApp, Telegram or Signal Use the app's own features to block and report the message. Ofcom says "You cannot usually forward these app messages to 7726." Lots of people already do it. Customers of four mobile networks made 89.8 million reports to 7726 between May 2024 and March 2025, Ofcom says. For threatening or malicious calls, Ofcom says to "call your phone company straight away and ask for their nuisance or malicious calls team". Direct answer: Act quickly, and don't feel embarrassed. If you've been charged for calls because of a scam, contact your phone company and report it to Report Fraud. If you've paid money or shared bank details, contact your bank or card provider immediately, or call 159 if your bank supports it, then report it to Report Fraud on 0300 123 2040, or to Police Scotland on 101 in Scotland. Caught out? What to do next I rang back and think I've been charged I paid money or shared bank details I'm in Scotland If you were tricked into sending money, telling your bank quickly matters. In 2025, £354.3 million was paid back to victims of APP fraud, 61% of the money lost, UK Finance says. The 159 service is available to customers of more than 99% of UK retail bank current accounts, and Stop Scams UK says it "cannot be spoofed or impersonated". Direct answer: You can't stop every one, but you can cut them down. Turn on your phone's call screening, ask your provider about call blocking, and register with the free Telephone Preference Service to cut sales calls, though Ofcom says "It will not block scam calls." Your scam-call toolkit: five things to switch on On an iPhone Go to Settings, Apps, Phone, then Screen Unknown Callers. Choose Ask Reason for Calling, or Silence to send unknown numbers to voicemail. Apple says calls aren't screened while you're roaming. On Android Look in your phone's call settings for spam and call-screening options. Ofcom gives Samsung's Smart Call as one example. With your provider Ofcom says some providers offer network-level filtering that blocks known scam numbers, and many landline providers offer call blocking, including anonymous call rejection. On a home phone Ofcom says call-blocking handsets can block withheld numbers or numbers not in your contacts. The TPS Free, online or on 0345 070 0707. It tells legitimate marketers you don't want sales calls, but Ofcom says "It will not block scam calls." For more on landlines, including what works and what doesn't, see our guide to what actually stops nuisance calls in the UK. If your home phone has moved to digital voice, it's worth asking your provider which call-blocking features it offers; our digital voice guide explains the change. Direct answer: Not on Ofcom's measure: it says the number of people who report that they've recently had a suspicious call has fallen over the last four years. But telecoms still matter. UK Finance says 17% of APP fraud cases in 2025 began via telecommunications, typically higher-value scams, and they made up 28% of the money lost. Where APP fraud started in 2025: share of cases and of money lost UK fraud in 2025: the headline numbers £1.28bn stolen through payment fraud in the UK in 2025, up 4% UK Finance £576.4m lost to APP fraud, up 19%, from 248,070 cases UK Finance Down 12% impersonation fraud losses, with cases down 11% UK Finance 61% of APP losses paid back to victims, £354.3 million UK Finance Phone companies are blocking scam calls too. An Ofcom spokesperson said on 2 October that "telecoms companies are blocking millions of scam calls every month". Ofcom doesn't give yearly figures for the fall in suspicious calls on that page, so we haven't charted any. Direct answer: Since February 2024, Ofcom has run an enforcement programme looking at phone and text scams. Tismi's case was part of it, and Ofcom has open investigations into other providers, including Xtra Phones UK from 21 October 2026. An open investigation is not a finding of wrongdoing. How the protections are building up, 2022 to 2027 There's more on the way for calls from abroad. From 15 July 2027, under Ofcom guidance, calls from abroad that show a UK mobile number starting +447 will appear as withheld unless the call can be verified, which Ofcom says will stop scammers outside the UK showing a fake UK mobile number. Ofcom says some genuine calls, for example from people roaming abroad, may also show as withheld. Direct answer: No. Report Fraud replaced Action Fraud on 4 December 2025 for England, Wales and Northern Ireland. You can report at reportfraud.police.uk or on 0300 123 2040. In Scotland, call Police Scotland on 101. Three changes worth knowing Action Fraud is now Report Fraud Since 4 December 2025, report fraud in England, Wales and Northern Ireland at reportfraud.police.uk or on 0300 123 2040. In Scotland, call Police Scotland on 101. Ofcom now regulates premium-rate numbers Ofcom formally took over from the Phone-paid Services Authority on 31 January 2025. Fake UK mobile numbers from abroad From 15 July 2027, calls from abroad showing a UK mobile number (+447) will appear as withheld unless the call can be verified. Direct answer: Talk about the warning signs and help them set up call blocking. Ofcom says to "Help them set up call-blocking tools on their mobile or home phone" and to encourage them to check with you, or another trusted person, before sending money. A five-minute chat that helps Ofcom notes that scammers often target older people, people living alone or anyone who might be more vulnerable, so a quick check-in helps. Our family checklist for setting up broadband for an older relative covers this and more, and Ofcom's Consumer Hub brings together its tips on protecting yourself from scams. Reviewing your phone and broadband deal anyway? Put in your postcode to see the deals we can find for your home, sorted by price. It's a good moment to ask any provider what call blocking it offers, too. In summary Alex's closing thought A lot of us feel it's rude not to ring back. It isn't. Anyone who needs you can leave a message or find another way, and you can always contact an organisation on a number you've looked up yourself. The encouraging part of this story is that the system is pushing back: Ofcom is taking action on companies that don't check who they hand numbers to, fewer people say they've recently had a suspicious call, and every text to 7726 alerts your network to investigate and potentially block the number. We'll update this page when Ofcom publishes its full decision or new findings. Stay safe Helping family Know someone who always rings back missed calls? Share this with them. The key advice takes a minute to read and could save them money. You are welcome to quote and link to this article. Please credit Ofcom for the enforcement findings and advice, UK Finance for the fraud figures, and BroadbandSwitch.uk for the charts and summaries, and link to this page. In a sentence: On 21 October 2026, Ofcom fined Tismi £437,500 after about 366,000 of its phone numbers were exposed to potential misuse, and its advice to consumers is not to call back numbers they don't recognise, to hang up on scam calls and to report scam calls and texts to 7726 for free. No. Ofcom says don't call back if you don't recognise the number. Missed-call scams are designed to get you to ring back, and calling back can connect you to a premium-rate number. If you think it might matter, contact the organisation on a number from its official website. Ofcom says to be especially careful with numbers beginning 070, 076, 084, 087, 090, 091 or 118, and with unfamiliar international numbers. 070 and 076 numbers begin with 07, so they can look like mobile numbers. It's another name for a missed-call scam. Automated systems call large numbers of phones, the call lasts under a second and shows as a missed call, and if you ring back you can be connected to a premium-rate service and charged while you stay on the line. Yes. Ofcom says reporting to 7726 is free. It spells SPAM on a phone keypad, and a report alerts your mobile provider to investigate and potentially block the number. Ofcom says: "Open recent calls, select the number, then copy or share it in a text to 7726." For a scam text, forward the message itself to 7726. Usually not. For WhatsApp, Telegram and Signal, Ofcom says to use the app's own features to block and report the message. Contact your phone company. If the number began 0871, 070 or 09 and you think it was a scam, Ofcom says you can also complain to it. Ofcom formally took over regulating premium-rate services on 31 January 2025. No. Report Fraud replaced Action Fraud on 4 December 2025 for England, Wales and Northern Ireland. Report at reportfraud.police.uk or on 0300 123 2040. In Scotland, call Police Scotland on 101. 159 is a short number you can call to reach your bank safely, if your bank supports it. Stop Scams UK says it's available to customers of more than 99% of the UK's retail bank current accounts and "cannot be spoofed or impersonated". No. The Telephone Preference Service is free and tells legitimate marketers you don't want sales calls, but Ofcom says "It will not block scam calls." You can register online or on 0345 070 0707. Ofcom found Tismi passed phone numbers to business customers without proper checks, didn't monitor whether they were being misused and had no formal process for handling reports of misuse, between at least November 2022 and January 2025. About 366,000 numbers were exposed to potential misuse. Not on Ofcom's measure. It says the number of people who report that they've recently had a suspicious call has fallen over the last four years. UK Finance also reports that impersonation fraud losses fell 12% in 2025, though fraud that starts via telecommunications still accounts for 28% of APP fraud losses. Written by Dr Alex J. Martin-Smith, Founder of BroadbandSwitch.uk (LinkedIn). Reviewed by Adrian James, Broadband Editor. Published 22 October 2026. On 21 October 2026 we read Ofcom's news release and case pages on Tismi and Xtra Phones UK, its enforcement programme, its releases on the Primo Dialler, Vonage Business and Voxbone investigations, premium-rate services and messaging scams, its October 2026 scam warning and scam advice pages, its statements on calls from abroad, 070 numbers and sub-allocated numbers, its 2020 update on 070 scam calls, UK Finance's June 2026 fraud figures, Report Fraud's launch notice, Stop Scams UK's 159 page and Apple's support page on unknown callers. Ofcom's full decision on Tismi isn't published yet, so we've used Ofcom's own summary. An open investigation is not a finding of wrongdoing. This is general information, not legal or financial advice. Corrections are logged publicly.Missed a Call From an Unknown Number? Ofcom's £437,500 Fine and What It Means for You
Why did Ofcom fine Tismi £437,500?
Rule (General Condition) What it covers, in short Ofcom's finding B1.6 Phone numbers a provider has been given must be used effectively and efficiently. Breached B1.8 Providers must take all reasonably practicable steps so the customers they pass numbers to follow the rules. Breached B1.9(c) Providers mustn't pass numbers on unless they'll be used effectively and efficiently. Breached B1.4 and B1.9(b) Numbers must be used in line with the National Telephone Numbering Plan. Investigated, not confirmed How do scammers get hold of real UK phone numbers?
What is a missed-call scam?
Which numbers should I never call back?
Should I call back a missed call from a number I don't know?
How do I report a scam call or text to 7726?
What should I do if I've already called back or lost money?
How can I stop scam calls reaching me?
Are scam calls getting worse?
What is Ofcom doing about scam phone numbers?
Company Investigation opened Status Tismi BV 16 October 2024 Closed: fined £437,500 on 21 October 2026 Primo Dialler 14 April 2025 Open. No outcome published Vonage Business Limited 24 September 2026 Open. No findings Voxbone SA 24 September 2026 Open. No findings Xtra Phones UK Ltd (trading as Compare The Networks) 21 October 2026 Open. No findings Is Action Fraud still the place to report a scam?
How can I help an older relative avoid missed-call scams?
Keep going: more on scams and staying safe
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Martin-Smith, A. J. (2026, October 22). Missed a call from an unknown number? Ofcom's £437,500 fine and what it means for you. BroadbandSwitch.uk. https://broadbandswitch.uk/insights/missed-call-scam-ofcom-tismi-fine/ Frequently asked questions
Should I call back a missed call from an unknown number?
Which phone numbers should I not call back?
What is a Wangiri scam?
Is 7726 free?
How do I report a scam call to 7726?
Can I forward WhatsApp scam messages to 7726?
What should I do if I called back and was charged?
Is Action Fraud still running?
What is 159?
Does the TPS stop scam calls?
Why did Ofcom fine Tismi?
Are scam calls getting worse?
References
Missed-Call Scams: What Ofcom's £437,500 Fine Means for You
Written by Alex Martin-Smith (LinkedIn) • Reviewed by Adrian James (LinkedIn)
Last reviewed: 22 October 2026
Quick summary: Ofcom fined Tismi £437,500 after about 366,000 numbers were exposed to potential misuse. Why not to call back unknown numbers, and how to report them.
15 Nov 2022
The start of the period covered by Ofcom's finding that Tismi broke the rules ("at least" from this date).
16 Oct 2024
Ofcom opens its investigation into Tismi, announced on 18 October 2024.
1 Jan 2025
The end of the period covered by Ofcom's finding. Over that period, about 366,000 numbers were exposed to potential misuse.
20 Jun 2025
Ofcom directs Tismi to block calls and messages to and from specific numbers, by 24 June. Tismi puts the block in place.
21 Oct 2026
Ofcom fines Tismi £437,500 and closes the case. The money goes to HM Treasury.
Break the chain at step 3. Ofcom says don't call back a number you don't recognise.
070076084087090091118Unfamiliar international numbers
Watch for look-alikes. 070 and 076 numbers begin with 07, just like mobile numbers. Ofcom has said "Consumers are generally unable to distinguish 070 numbers from calls made to mobile numbers".
Is the number saved in your contacts?
Did they leave a voicemail or send a message?
Whatever the answer: be especially careful with 070, 076, 084, 087, 090, 091 and 118 numbers and unfamiliar international numbers, and never give personal details on a call you weren't expecting.
Share of casesShare of money lost
Online
66%
32%
Telecommunications
17%
28%
Email
1%
7%
15 Nov 2022
Ofcom publishes its good practice guide on preventing misuse of sub-allocated numbers.
1 Feb 2024
Ofcom opens its enforcement programme into phone and text scams.
31 Jan 2025
Ofcom formally takes over regulating premium-rate services from the Phone-paid Services Authority.
14 Apr 2025
Ofcom opens an investigation into Primo Dialler. No outcome has been published.
4 Dec 2025
Report Fraud replaces Action Fraud for England, Wales and Northern Ireland.
24 Sep 2026
Ofcom opens investigations into Vonage Business Limited and Voxbone SA.
2 Oct 2026
Ofcom warns about job-offer and missed-call scams, and says it's investigating four providers.
21 Oct 2026
Tismi is fined £437,500, and Ofcom opens an investigation into Xtra Phones UK.
15 Jul 2027
Calls from abroad showing a UK mobile number (+447) will appear as withheld unless they can be verified.