Phone number spoofing
How scammers fake the number shown on your caller ID, and why you cannot trust a familiar number, even if it appears to be from your bank or a government body.
What is number spoofing?
Number spoofing is when a caller deliberately falsifies the telephone number shown on your caller ID display. Using widely available internet telephony (VoIP) software, fraudsters can make any call appear to come from any number, including your bank's genuine helpline, HMRC, the police, or even a number you already have saved as a contact.
This is technically technically simple and cheap to do. It is illegal when used to commit fraud in the UK under the Communications Act 2003, but the infrastructure is often based overseas, making enforcement difficult.
The key fact about caller ID
A phone number appearing on your caller ID does not prove who is calling. Your bank, HMRC and the police will never ask you to transfer money, withdraw cash, or share your PIN, regardless of what number is displayed.
Common spoofing scams
Bank impersonation
Scammers spoof your bank's genuine 0800 number and claim there is suspicious activity on your account. They ask you to transfer money to a "safe account", which belongs to them. This is the most financially damaging spoofing variant.
HMRC impersonation
Callers display HMRC's real helpline number (0300 200 3300) while threatening you with arrest or demanding immediate tax payment. HMRC does not call with arrest threats. This is always a scam..
Police impersonation
Fraudsters display a genuine police non-emergency number (101) or local station number while claiming your bank account has been compromised. No police force will ask you to withdraw cash or transfer money.
Neighbour spoofing
The caller displays a number with the same area code or prefix as your own number to appear local and increase the chance you answer. The call has no connection to your area.
Trusted contact spoofing
The caller uses the number of someone in your contacts — your GP surgery, employer, or a family member — to make you more likely to answer and trust them.
New UK rules on number spoofing — 2025/2026
Ofcom has introduced new Caller Line Identification (CLI) authentication requirements for UK telecoms providers as part of its Consultation on Tackling Scam Calls (October 2025). These require providers to verify that the number displayed in a call matches the originating network — making it significantly harder to spoof UK-originating numbers.
However, calls originating overseas — which account for a large proportion of spoofing scams — remain more difficult to control, as international networks are not subject to UK authentication requirements. The new Ofcom Organised Crime Communications (OCC) unit, launching April 2026, will have powers to identify and disconnect overseas networks used for UK scam calls.
How to protect yourself
- ✓If you receive an unexpected call from your bank or a government body, hang up and call back on a number you find independently — from their official website or the back of your card.
- ✓Wait at least five minutes before calling back on a landline, or use a mobile. Fraudsters can hold a landline connection open for up to two minutes.
- ✓Dial 159 to reach your bank's fraud team directly — this is routed differently and cannot be intercepted.
- ✓Your bank will never ask you to move money to a safe account, share your full PIN, or hand cash to a courier.
- ✓Check numbers you don't recognise on WhoIsCalling before calling back.