No caller ID, withheld and private number calls

A call that shows No caller ID, Withheld, Private number or Unknown has arrived without a number you can see. The caller may have chosen to hide it, or no number came through with the call. The honest answer to “who was it?” is that you normally can’t find out, and that includes here: with no number, there is nothing to look up. What you can do is decide whether to answer, stop the calls reaching you, and report the ones that break the rules.

What each label means

Phones and networks label these calls differently, so the same call can show as “Withheld” on one phone and “No caller ID” on another.

• Withheld or Private number. The caller has stopped their number being shown. Anyone can do it for a single call: BT says dialling 141 before a number stops yours being released.
• No caller ID or Unknown. No number came through with the call. That can be because the caller hid it, or because no number was passed on with the call. Your phone cannot tell you which.
• A call from abroad with no number. Treat it the same way: without a number there is nothing to check and nothing to ring back.

Can you find out who called?

Usually not. On a BT landline, 1471 tells you the last caller withheld their number, but does not give it to you. A number lookup, ours included, can’t help either, because there is no number to put in. If the caller left a voicemail or rings again with a number showing, you can check that number then with the reverse phone lookup.

Be wary of any app or website that promises to reveal a withheld number. We can’t point you to one that does it honestly, and a caller who really wants to be found will leave a message or ring back with their number showing.

Are withheld calls allowed?

For marketing calls, no. The Information Commissioner’s Office says a company making a marketing call must let its number, or another contact number, be shown to the person it is calling. Ofcom says the same of companies using automated diallers. So a sales call from a withheld number is breaking the rules, and you can report it to the ICO.

Some legitimate callers do withhold their numbers, for their own reasons. A genuine caller who needs you will leave a message, write, or ring again, so letting an unknown call go to voicemail costs you very little.

How to stop or reduce them

• On an iPhone: open Settings, tap Apps, then Phone, then Screen Unknown Callers, and choose Silence. Apple says this silences calls from unknown numbers and sends them to voicemail.
• On Android with the Google Phone app: open the Phone app, tap More, then Settings, then Blocked numbers, and turn on Unknown. Google says this blocks calls from private or unidentified numbers. Other makes of phone have their own settings.
• On a landline: ask your phone provider what it offers for blocking withheld or anonymous calls, and whether it costs anything.
• Sales calls in general: register with the free Telephone Preference Service. Silent calls can be reported to Ofcom online or on 0300 123 3333. How to stop spam and nuisance calls covers every route.

When a number does show

A number on your screen can be faked too, so it is not proof of who called. See caller ID spoofing, and for every free way to find out who rang, read how to find out who called you.