Can a caller fake their number? Caller ID spoofing in the UK

The number on your screen is information the caller’s phone system sends, and it can be set to almost anything. That is caller ID spoofing. It is how a scammer rings you showing your bank’s real switchboard, a local-looking landline, or a mobile number that belongs to somebody who has no idea their number is being used.

What the phone companies must now block

• Calls from abroad showing a UK landline number. Since 29 January 2025, under Ofcom guidance, UK phone companies have had to identify and block calls from abroad that falsely display a UK landline number, apart from limited legitimate cases. BT, which started doing this voluntarily, reported stopping up to a million such calls a day within its first month.
• Calls from abroad showing a UK mobile number. On 15 July 2026 Ofcom finalised strengthened guidance: phone companies should withhold the caller ID on calls that appear to come from a UK mobile roaming abroad unless they can verify it is genuine.

None of that stops every spoofed call. A spoof can still start inside the UK, and a blocked caller ID is a withheld number, not a warning. The safe habit stays the same: judge the call by what it asks you to do, not by the number it shows.

Numbers that cannot be real

Some numbers are not in use by anyone, so a call showing one was spoofed:

• Numbers in a range Ofcom has never allocated to any phone company. Every GotMyNumber number page says whether the range was allocated, and to whom.
• Ofcom’s drama ranges, such as 07700 900000 to 07700 900999 and 020 7946 0000 to 020 7946 0999, set aside for film and television and not allocated to any phone company.
• Numbers of the wrong length for their code. The UK area code list gives the right length for every code.

If your own number is being spoofed

You may find people ringing you back, angry about calls you never made. There is no way to stop someone typing your number into their system, but you can tell your phone provider, record a voicemail greeting that says your number is being misused, and check your number’s page here to see what people have reported. A number reported by people on several different networks in a short time, when you made no calls, is a sign of spoofing rather than of anything you did. If it is your business’s number, say on your website how you do and do not contact customers, so someone who gets a spoofed call has something to check it against.

What to do with a spoofed call

• Hang up, and ring the organisation back on a number you found yourself.
• For a call claiming to be your bank, use 159.
• Report the number you saw, saying what the caller claimed to be. Even if the number was borrowed, it warns the next person that it is being used.