What Does No Caller ID Mean? UK Guide to Withheld Calls and Scams

"No Caller ID", "Withheld", "Private number" or "Unknown" on your phone screen means the person calling has hidden their number, or the phone network could not pass it on. Many of these calls are harmless, such as a friend or an organisation that withholds its number. But scammers also hide or fake their numbers, so it pays to be careful. This guide explains what No Caller ID means in the UK, who might be calling, and how to protect yourself and older relatives from scam calls.

What No Caller ID means

• The caller has hidden their number. In the UK, anyone can hide their number for a single call by dialling 141 before the number. BT says you can also ask your phone company to withhold your number on every call.
• The number could not be shown. Ofcom says that even with caller display switched on, your phone will not always show a number.
• Different phones use different words. You might see "No Caller ID", "Withheld", "Private", "Unknown" or "Anonymous". They all mean you cannot see who is calling.

Who might be calling?

• Genuine organisations. Some businesses and organisations withhold their number when they call.
• Friends and family. Some people withhold their number by default without realising.
• Silent or abandoned calls. Ofcom says most silent calls come from automated dialling systems in call centres. Companies using these systems must display a number.
• Scammers. Criminals may hide their number, or fake one to look like your bank or another trusted organisation.

Withheld numbers and fake numbers

A hidden number is not the only warning sign. Ofcom warns that scammers can change the number that appears on your screen, so a call can look as if it comes from your bank, HMRC, a delivery company or even Ofcom. This is called number spoofing. Age UK says the same: scammers can mimic an official number to trick you into thinking they are from a bank or utility company.

So a call can be dangerous whether it shows a number or not. And a caller who knows your name, address or other details is not necessarily genuine. Ofcom says scammers get personal information from data breaches and public sources.

Marketing calls and the law

Ofcom says that when a company makes a live sales call, it must tell you who it is and give you a contact number. If you ask it to stop calling, it must stop. Companies should not make marketing calls to you if you are registered with the Telephone Preference Service (TPS), unless you have agreed to hear from them. Recorded marketing calls need your explicit consent.

The TPS is free. You can register online or call 0345 070 0707. Ofcom says it can take up to 28 days for calls to reduce. The TPS will not stop scam calls. Age UK warns that callers asking you to pay to renew TPS membership are scammers, because the service is free.

Common phone scams to watch for

Age UK lists several common phone scams in the UK, including:

• Bank scams. A caller says there is fraud on your account and asks for your PIN, or tells you to hand your card to a courier. Your bank would never do this.
• Fake police. A caller says they are "undercover police" investigating your bank and asks for your card details.
• Computer repair scams. A caller says your computer has a virus and asks you to download software.
• HMRC and Council Tax scams. Calls about tax refunds, unpaid tax or Council Tax rebates.
• AI voice scams. A voice that sounds like a family member says they are in trouble and need money urgently.

Ofcom also warns about missed call scams. A number rings once and hangs up, hoping you call back and get charged at a premium rate. Be especially careful with numbers starting 070, 076, 084, 087, 090, 091 or 118, and unfamiliar international numbers.

How to hide your own number

If you want to hide your number when you call someone:

1. For one call: dial 141 before the number.
2. For every call: ask your phone company to withhold your number permanently.
3. To show your number once when it is permanently withheld: BT says you dial 1470 before the number. Check with your own provider.

Bear in mind that some people do not answer withheld calls. When you need to reach a GP, a carer or a family member, it may be better to show your number.

How to find out who called

On a landline, Ofcom suggests trying 1471 after a call to hear the last number that called you. On a mobile, look in your recent calls list. If you do not recognise a number, Ofcom suggests searching it online, as scam numbers are often reported by other people.

How to stop or screen withheld calls

• Anonymous call rejection. Ofcom says many landline providers offer call blocking or filtering, including blocking anonymous calls. Contact your provider to find out what is available. Some services may cost extra.
• Call-blocking phones. Some handsets can block withheld numbers or numbers not in your contacts. Ofcom says these can be especially useful for older or vulnerable people.
• Smartphone settings. Most smartphones let you block numbers, and some can screen or silence unknown callers. Ofcom names Apple's Screen Unknown Callers and Samsung's Smart Call as examples.
• Spam filters. Many phones have built-in spam filters for calls and texts. Check they are switched on.
• Answerphone or voicemail. Age UK suggests using an answerphone or voicemail to screen calls. A genuine caller can leave a message.
• A free call blocker. Age UK says the TPS offers a free call blocker to people identified as most vulnerable by a doctor, Trading Standards or their council.

What to do if you answer a suspicious call

Ofcom's advice is to stop, check and report:

1. Do not give personal details to anyone who calls you unexpectedly. This includes your name, address, date of birth, bank details, PIN, passwords or National Insurance number.
2. Hang up if you have any doubt. It is always safe to hang up. A genuine caller will give you time.
3. Do not be rushed. Scammers use urgency to stop you thinking clearly. Genuine callers will not ask you to keep a call secret.
4. Call back on a number you trust, such as one on the organisation's official website or your statement, not one the caller gives you.
5. Check the line is clear. Age UK warns that scammers can keep the line open after you hang up. Use a different phone, call someone you know first, or wait 10 to 15 minutes before calling.
6. Agree a safe word with close family, so you can check it really is them.
7. Talk to someone you trust before you send money or share details.

Call 159 to reach your bank safely

If you get a call about your bank account that worries you, hang up and call 159. It connects you to your own bank. Stop Scams UK, which runs the service, says 159 covers more than 99% of UK retail bank current accounts, and that it cannot be spoofed. You can also call the number on the back of your bank card.

How to report scam and nuisance calls

• Scam calls: report to Report Fraud, which replaced Action Fraud, online or on 0300 123 2040. In Scotland, call Police Scotland on 101.
• Mobile scam calls and texts: forward the number or text to 7726 for free, so your provider can investigate and block it.
• Unwanted marketing calls and texts: report to the Information Commissioner's Office (ICO) online or on 0303 123 1113.
• Silent or abandoned calls: report to Ofcom online or on 0300 123 3333.
• Threatening or abusive calls: call your phone company's nuisance calls team and the police on 101, or 999 if you are in immediate danger.

If you have shared details or sent money, contact your bank straight away. For free, confidential support, Ofcom points to Citizens Advice on 0808 223 1133 (Advice Direct Scotland on 0808 164 6000 in Scotland). You can also call the Age UK Advice Line free on 0800 678 1602.

Helping an older relative

Scammers often target older people and people who live alone. Ofcom suggests talking to them about common scams, helping them set up call blocking, and encouraging them to check with you before sending money or sharing details. If you look after someone, our family and carers guides have more support. You may also find our guide to the three rings safety call useful for staying in touch.

Frequently asked questions

What does No Caller ID mean on my phone?

It means the caller has hidden their number, or it could not be shown. You can still answer or reject the call as normal.

Is a No Caller ID call a scam?

Not always. Some genuine people and organisations withhold their number. But scammers also hide or fake their numbers. Do not give personal or bank details to anyone who calls you unexpectedly, whatever number they show.

Can I find out who called from a withheld number?

Not easily on your own. On a landline you can try dialling 1471 after the call. If withheld calls are threatening or abusive, call your phone company and ask for its nuisance or malicious calls team, who can take steps to help protect you, and report it to the police on 101.

How do I block No Caller ID calls?

Ask your landline provider about anonymous call rejection, use a call-blocking handset, or turn on your smartphone's setting to silence or screen unknown callers. If you block all withheld calls, you may miss some genuine ones, such as from an organisation you deal with.

Can answering a No Caller ID call hack my phone?

Ofcom's advice focuses on what you do during and after the call. Do not press buttons, follow instructions to install software, or click links in texts that follow the call. If you clicked a link or installed something, contact your mobile provider.

Sources

• How to protect yourself from scam calls, texts and messages (Ofcom)
• What to do about a scam call, text or message (Ofcom)
• Unwanted calls, texts and emails (Ofcom)
• Types of scam calls, texts and messages (Ofcom)
• Phone scams: dealing with cold and nuisance calls (Age UK)
• How to stop nuisance phone calls (Which?)
• Report Fraud: what does this new era of fraud reporting mean? (Which?)
• 159 (Stop Scams UK)
• How do I withhold my telephone number? (BT)

Feature image photo by Karolina Grabowska on Pexels