An unknown number is calling me: what to do, step by step

An unknown number is calling me: what to do, step by step

Getting calls from numbers you don't have saved is increasingly common. Before answering or calling back, it pays to check who's behind it: the NoCall community keeps a large database of user reports on phone numbers.

1. Don't answer with your details

If you decide to pick up, listen first. Don't say your full name, don't confirm your date of birth or National Insurance number, and don't share codes you receive by text. A genuine caller will say who they are without asking for sensitive details upfront.

2. Look the number up on NoCall

The NoCall database holds a large catalogue of numbers identified by the community. For each number you can see its risk score, its category and comments from other users:

• Risk score — from 0 (safe) to 100 (dangerous).
• Category — spam, telemarketing, scam, debt collection, surveys.
• Comments — what other users who got the same call reported.

3. Read the prefix

The first digits give you immediate clues about the kind of call (our prefix directory has more):

• 07 — UK mobile. Careful: 070 numbers look like mobiles but are personal numbers charged at a much higher rate.
• 01 and 02 — landlines linked to a geographic area.
• 0800 and 0808 — freephone. 03 numbers are charged at the standard rate, like a landline; 030 numbers are used by public bodies and charities.
• 084, 087, 09 and 118 — business-rate and premium-rate numbers: calling them back can be expensive. Check current prices in the GOV.UK guide to call charges.
• + followed by a country code — an international call: check the country before calling back, as it may be expensive. A UK number written as +44 7700 900123 is the same as 07700 900123.

4. Decide: call back, block or ignore

• Low risk and a plausible reason — call back as normal.
• Spam or pushy telemarketing — block the number and report it on NoCall. Unwanted sales calls can also be reported to the ICO.
• Possible scam — don't call back; if you've already given out details, contact your bank and report it to Report Fraud (formerly Action Fraud) on 0300 123 2040, or to Police Scotland on 101 if you're in Scotland.

5. Protect yourself going forward

Turn on your phone's spam filter and the NoCall app to identify incoming calls automatically, and register your number free with the Telephone Preference Service to cut down sales calls (it won't stop scammers). If the call felt suspicious, also read our step-by-step guides.

Should I answer a call from an unknown number?

You can answer, but never share personal or bank details. If the call matters, they'll leave a message or call back. Afterwards, look the number up on NoCall to see whether other users have reported it.

How can I find out who called me from an unknown number?

Look the number up on NoCall: you'll see its risk score, category (spam, telemarketing, scam), network and comments from other users who got the same call.

Is it dangerous to call back an unknown number?

It can be: 09 premium-rate, 118 and 070 numbers can charge high rates when you call them. Always check the number on NoCall before calling back.