A call that appears to come from a familiar UK number is not necessarily what it seems. Ofcom, the communications regulator, explains that scammers can fake the number that appears on your screen, a technique known as number spoofing. This article sets out what Ofcom advises, what the Telephone Preference Service (TPS) can and cannot do, and where to report, with the differences between nations spelled out.
Why the number on your screen proves nothing
Ofcom’s guidance says plainly that scammers can fake the number that appears, so a display showing a bank, a phone company or a local number is not proof of who is calling. The practical rule that follows is that you should judge a call by what is being asked of you, not by the caller ID.
What to do during a suspicious call
Ofcom’s advice for calls is consistent and short:
- Never give personal details to someone who has called you unexpectedly.
- Hang up if you have any doubt about who is calling.
- Call the organisation back using a number from its official website or another published number, not the number the caller gave you.
These steps work even when the caller sounds professional or already knows some of your details, because they take control of the conversation away from the caller.
What the Telephone Preference Service does not do
Registering with the TPS is worthwhile for cutting down legitimate sales calls, but Ofcom is explicit about its limit: it tells legitimate marketers you do not want sales calls, and it will not block scam calls. Criminals ignore it, so registering should not make you relax about unexpected calls.
For blocking, Ofcom points to several options. On mobiles these include built-in spam filters, network-level filtering and trusted apps. On landlines they include caller display, provider filtering and call-blocking handsets.
Reporting texts and calls to 7726
Ofcom’s guidance says to forward suspicious texts to 7726, which is free of charge. This alerts your mobile provider, which can investigate and potentially block the number. Ofcom also says calls can be reported: open your recent calls, select the number, then copy or share it in a text to 7726. You must provide the number for the provider to investigate. Messages sent through apps such as WhatsApp, Telegram and Signal cannot be forwarded to 7726, so use each app’s own reporting tool for those.
Reporting fraud, by nation
Ofcom does not investigate individual scam call cases, though it notes that complaints can inform investigations and enforcement action. Where to report depends on where you live:
- England, Wales and Northern Ireland: report to Report Fraud (0300 123 2040), the national fraud reporting service. If you think you have been the victim of caller ID spoofing, Ofcom says to tell Report Fraud.
- Scotland: contact Police Scotland on 101, or 999 if you are threatened. Ofcom also lists Advice Direct Scotland’s consumer service on 0808 164 6000.
- If your bank details were compromised: Ofcom says to contact your bank or credit card company first.
What Ofcom is doing about spoofing
In an announcement about scam messages, Ofcom set out new requirements for mobile providers. Providers must block numbers used by scammers, block scam messages in transit by detecting malicious weblinks and phone numbers, and set volume limits for pay-as-you-go SIM cards. For business messaging, providers must carry out upfront and ongoing “Know Your Customer” checks and prevent fake sender names by verifying them against business information.
The same announcement covers calls. Ofcom says it has introduced strengthened guidance requiring telecoms companies to withhold caller ID from calls that appear to originate from UK mobile numbers roaming abroad, unless their validity can be verified. It cited a finding that 40% of UK mobile users had reported receiving at least one suspicious message in the previous three months. These measures are aimed at reducing the number of scam contacts that reach you, but they do not remove the need for the personal habits above.
A note on scam calls that mention Ofcom
Ofcom warns that calls claiming to come from Ofcom itself are fraudulent. It also directly handles complaints about premium-rate numbers, which use the 0871, 070 and 09 prefixes, through its own complaints process. That is a different matter from scam calls in general, which Ofcom directs to Report Fraud or, in Scotland, to Police Scotland.
The bottom line
Caller ID can be faked, so never treat it as proof of identity. Hang up if in doubt, give no personal details and call back on a number you find yourself. The TPS will not stop scam calls, but 7726 lets you report scam texts and numbers to your mobile provider for free. Report fraud to Report Fraud in England, Wales and Northern Ireland, or to Police Scotland in Scotland, and contact your bank first if financial details were at risk.