Legitimate Ways to Find Someone's Phone Number

Sometimes you need a number you don't have: a company's customer service line, a tradesperson someone recommended, an old friend you've lost touch with. There are plenty of legitimate ways to find one. There are also plenty of sites promising more than they can deliver. Here's what actually works.

For businesses and organisations

Go to the official website

This is the most reliable source. Look on the Contact us page or in the footer. If you're contacting your bank, energy supplier or a government department, always use the number from the official site or your paperwork, never one from an advert or search result you haven't checked.

Check your paperwork

Bills, statements, letters and the back of your bank card all carry verified numbers. These are the safest to use if you think a call might have been a scam.

Search maps and business listings

Map apps and business directories usually list a phone number for shops, restaurants and trades. Cross-check it with the business's own website if you can.

Directory enquiries

118 services can find business and listed residential numbers, but calls are expensive. Check the price first.

For people

Ask a mutual contact

The simplest and most respectful way. Ask a friend, colleague or relative to pass on your number, so the other person can choose whether to get in touch.

The phone book

Landline numbers are listed in the public directory unless the owner has gone ex-directory. Mobile numbers aren't listed at all in the UK.

Social media and professional networks

Many people can be messaged directly on social or professional networking sites, even if their number isn't shown. Send a message rather than hunting for a number.

What doesn't work

• Paying to "unlock" a mobile number. There's no public register of UK mobiles, so these services rarely have anything real to sell.
• Trying to trace a withheld number. Only the phone networks and police can see it.
• Collecting personal details without a good reason. Data protection law protects private individuals, and harassment is a crime.

Working the other way: who does this number belong to?

If you have a number and want to know who it is, that's a different job. Search it on Who Called Me Check to see the line type, area, cost to call and what other people have reported. For businesses, searching the number in quotation marks on a search engine often brings up their website.