Most people automatically check Caller ID when they get a phone call to see who's ringing them. However, rather than seeing the caller's name or number, you may read that the number is 'private', 'withheld' or 'unknown'.

It's not always a straightforward process to call someone back if they phoned you with an unknown number. You won't be able to manually dial the digits because they won't have been listed on your phone, and your phone may not have been able to record where the call came from.

There are several methods you can use to try and phone an unknown number back. However, it's important to remember that they aren't guaranteed to work. You may have to wait for the caller to ring you back or contact you in another way.

In this guide, we'll look at what unknown numbers are, how callers can hide their numbers and the ways you may be able to call unknown or withheld numbers back.

An unknown number is a number that your device doesn't recognise. The number may not necessarily be withheld; it could be that your service provider is unable to register the phone number. This can happen for a number of reasons, such as a system malfunction. However, a number is usually listed as unknown if the caller has hidden their number somehow.

You can't manually redial an unknown number because your phone won't have shown the digits. Instead, you may be able to call the number back through other methods. This will only work if the number wasn't 'withheld' or 'private' as otherwise, your phone won't have logged the relevant caller information.

Continue reading to find out how you can call an unknown number and whether it's safe to call these types of numbers back.

You can find out the last number that called your phone by dialling 1471. This is a free BT system that should work on most calls to your landline. However, if the caller chose to withhold their number, you will hear an automated message after dialling 1471 that says the last caller withheld their number, and you can't call them back.

You can also press '3' which will automatically call back the last caller. This service costs 35p per call plus your standard network rate. Again, this method won't work if the caller chose to hide their number. It will only work if the 'unknown' message appeared through a network error rather than the caller's choice.

It's important to remember that 1471 will only identify the last person to have called you. If someone else phones before you have a chance to identify the unknown number, you won't be able to use the 1471 or dial 3 options.

Some networks don't support the 1471 option. You should contact your phone carrier to find out how you can recover the number from the last caller to your phone.

Can I disable the 1471 feature?

You can't disable the 1471 feature on your landline. However, if you dial 1475 and follow the instructions you hear, you should be able to erase the number from your last incoming call. This means the number can't be called again through 1471.

In North America, you can dial *69 to phone back the number of your last incoming call. You can do this whether you answered the original call or not. This method works on both landlines and mobile phones. It's worth remembering that your service provider may set a time limit for this method. For example, you may have to dial *69 within 30 minutes before your phone forgets the number.

You won't have access to the actual phone number when you use *69. Instead, your phone will automatically call back the number without you having to dial the digits. The caller may not answer your phone call, but you might be able to work out their identity through their voicemail.

This method won't work if the caller withheld or blocked their number when they phoned you. Your phone won't have access to their number and, therefore, won't allow you to call it back. Instead, you would have to hope that the caller phoned you back or left a voicemail as to how you can contact them.

It's a good idea to avoid phoning back numbers that you aren't familiar with. There's a chance that you might fall victim to a missed call scam and be charged money for the call. Some scammers use premium rate phone numbers which means you will be charged when you call them. They phone and hang up after the first ring in the hope that you will phone them back out of curiosity.

You could also accidentally make an international call if you phone the unknown number. This could end up costing you a large sum of money depending on your service provider and phone package.

It's advisable to wait for the caller to leave a voicemail or contact you another way (such as via text or email). Most legitimate companies don't hide their number when they call customers or clients. You can also ask your friends and family members who hide their numbers to give you an estimate of when they will call you so that you know to answer the phone.

As previously stated, a number may be unknown because of a network error or because the caller chose to block or withhold their number.

Withholding a number means that your caller ID won't be displayed on the recipient's phone display. The recipient's phone won't register the number even if they have it saved in their phone's contacts.

You can temporarily withhold a number by dialling 141 before your phone someone. You'll have to dial 141 for each phone call you make if you want to withhold your number on multiple calls. You will have to contact your phone company to find out how to withhold your number on all phone calls.

You can't phone numbers that have been withheld because your phone won't have registered the number.

Withholding your phone number can help ensure your privacy. You might want to phone companies and individuals without giving away your contact number. This can help prevent scam or spam calls because fewer people will have access to your phone number.

Scammers often set their number to unknown so that it's harder for them to get reported. It also means that you can't block their number because your phone won't have registered it. This means they can continue calling you unless you block all calls from unknown or withheld numbers.

You might receive more scam calls if you answer a call from an unknown number. Scammers use automated machines that randomly call a list of numbers in the hope that someone answers. Once you pick up or phone the number back, your number will be marked as active. The scammers may pass your number on to other scammers because they think you are more likely to answer or phone back these types of calls.

Not all callers who withhold their numbers are scammers or trying to sell you something. It may be someone you know who prefers to use a private number for security reasons. However, an 'unknown number' often indicates that the caller is trying to hide their identity for some reason. This could be because they don't want you to phone them back or because they don't want you to have their number and report it.

You can set your phone to block all incoming calls that are from withheld or unknown numbers. This can limit the number of scam calls you get. Any scam calls that come through from listed numbers can be easily blocked through your smartphone's settings (or by contacting your service provider). You should be aware that you this will also block incoming calls from family and friends who hide their numbers.

Will I be charged if I call an unknown number?

You should be charged at your standard network rate if you manage to call an unknown number back. If you phone the number back by dialling '3', you may be charged an extra fee (BT charges 35p per call).

Some scammers use premium rate numbers so that they are paid when people call them back. It's a good idea to avoid calling back numbers if you don't know who is using them. If the call is important, the caller can always phone you again and leave a message or contact you in another way.

Premium rate numbers can charge up to £3.60 per minute plus your network's access rate and between 5p to £6 per call. These charges apply whether you call from a mobile phone or a landline. The scammer will usually try to keep you on the line for as long as possible in order to charge you the most money. They may play hold music, so you stay waiting on the line or try to engage you in conversation.

Can I block calls from withheld numbers?

There are multiple ways you can block calls from unknown or withheld numbers. BT offers a service called Anonymous Call Reject which stops calls from people who have withheld numbers. The anonymous call rejection system only allows calls through that have shared their number. BT charges £7.50 per month for this service.

On iOS 13 and later, you can turn on Silence Unknown Callers to stop unknown numbers from calling your iPhone. This system blocks unwanted calls from numbers that you haven't made outgoing calls to and numbers that aren't saved in your contacts list. Callers will be directed to leave a voicemail and the calls will be logged in your recent calls list. You can turn this system on via the Phone sections in Settings.

On Android smartphones, you should be able to block unknown numbers through your device's settings. You should be given an option in your Phone app to block numbers listed as unknown. However, you will still be able to receive calls from numbers that aren't listed in your Contacts as long as the number isn't withheld.

By its very definition, it can be difficult to call unknown numbers because you don't know who's calling you or the digits of their number. However, in the UK, you can try to use 1471 to phone the telephone number from the last incoming call you received. The US equivalent to 1471 is *69. In some cases, you have to dial these digits within a set period of time, such as 30 minutes after the call was made.

You can block unwanted calls from hidden numbers through your phone settings or by getting in touch with your service provider. This can reduce the number of scam calls you recieve and ensure that you only get calls from people you know.