How to keep your landline number when switching broadband in the UK

Yes, you can keep your landline number when you switch broadband provider. The process is called number porting, and under Ofcom rules your current provider has to release your number to a new one. In most cases it is free, it happens as part of the switch, and your friends, family, GP surgery and bank never need to know anything has changed.

The one thing that trips people up is timing. If you cancel your old service before the transfer completes, your number can be released and lost permanently. Keep reading and you will see exactly how to avoid that, along with realistic timeframes, the costs to watch, and what happens if you are moving house.

Can you keep your landline number when switching broadband?

In nearly all situations, yes. Any landline number you have been using belongs to you, and under Ofcom regulations you are entitled to port it to a new provider. Your current provider cannot refuse to release it or hold it hostage. It works on the same principle as keeping your mobile number when you change network.

The major providers all support landline number transfers, so switching between them rarely causes a problem. There are only two situations where you might not be able to keep your number, both covered further down: moving to a different area code, and switching to a provider that does not offer a landline at all.

Why switching now often means moving to digital voice

Here is the bit that worries a lot of people, so let us clear it up. The UK's old analogue landline network, the Public Switched Telephone Network (PSTN), is being switched off. Government guidance confirms that all users of the Openreach PSTN need to be migrated to new services by 31 January 2027.

What that means in practice is that your landline will run over your broadband connection rather than down copper wires. This is called digital voice, or VoIP (Voice over Internet Protocol). BT calls its version Digital Voice, Sky calls it Sky Talk, and Virgin Media calls it Virgin Phone. The service is the same idea in each case: your calls travel over the internet.

Crucially, this does not affect your number. You keep it, and it ports exactly as it always has. What changes is how you plug in. Instead of a phone socket in the wall, you connect your handset to a phone port on your broadband router. Many modern routers have a green telephone socket on the back for this. If yours does not, a small device called a VoIP adapter (sometimes called an ATA) lets you carry on using your existing corded or cordless phone.

The change is already well advanced. Over two-thirds of UK landlines had moved to digital voice by early 2026. So if you are switching provider now, your new service will almost certainly be digital voice, and your number transfers the same way regardless.

A word about 999 and power cuts

Because digital voice depends on your broadband and mains electricity, calls will not work during a power cut. UK providers must offer a solution, usually a battery backup unit, or a free mobile handset for vulnerable customers. If you or someone in your home relies on a personal alarm, care line or pendant service, ask about this before you sign up.

How number porting works in the UK

Number porting simply moves your existing number from one provider to another. The number stays identical; only the network handling your calls changes.

You deal with your new provider, not your old one. When you sign up, you tell them you want to transfer your existing number rather than take a new one. They then contact your current provider on your behalf and arrange everything. To do this they will usually ask you to sign a Letter of Authority (LOA), sometimes called a porting form, which gives them permission to request the transfer.

Since September 2024, broadband and landline switching in the UK has been simplified by the One Touch Switch process. Under these rules your new provider manages the whole switch, including cancelling your old service, so you do not have to ring your old provider to give notice. Number porting is handled at the same time, so your number moves across when your new broadband goes live.

Step by step: how to keep your number when you switch

1. Choose a new provider that supports porting. Before signing up, confirm they can port your number from your current provider, ask whether there is any charge, and check how long it will take.
2. Sign up and select "transfer my number". During sign-up you will normally be asked whether you want to keep your existing number or take a new one. Choose to transfer.
3. Gather your details. You will need your full landline number including the area code, your current provider's name, the account holder's name exactly as it appears on the bill, and your billing address. A recent bill or account number helps.
4. Complete and return the Letter of Authority. Check every detail matches your latest bill, sign it, and send it back. This is usually done by uploading a scan, sending a photo or posting it. Incorrect details are the single most common cause of delays.
5. Let the providers coordinate. Your new provider submits the request and the two providers arrange the switch. Your existing line keeps working during this stage, and your new equipment may arrive.
6. Wait for your go-live date. On the agreed date your number stops working on the old line and starts on the new service, usually within a few hours.
7. Plug in and test. Connect your handset, ring a mobile, and get someone to call you back to confirm it all works.

Old provider versus new provider: who to tell and when

Under One Touch Switch, you contact only your new provider. They handle the transfer and the cancellation of your old broadband and landline. You do not need to phone your old provider separately to arrange the port or to close the account.

The important corollary is this: do not cancel your old service yourself. Your number must remain active on your current account to be ported. If you close the account first, the number can be released back into the pool and lost for good. Leave the old service running until your new broadband and landline are confirmed working.

How long the transfer takes and what it costs

Timeframes vary a little depending on the provider and the type of service. As a guide, standard landline number ports typically complete within 7 to 14 working days. Some residential VoIP ports move faster, in the region of 5 to 10 working days. Full fibre (FTTP) installations can take longer if an engineer needs to attend to fit the connection.

On the go-live day itself, any interruption is short. You may notice calls briefly not connecting, or an incoming caller hearing a "number not recognised" message, but service normally returns within a few hours.

On cost, number porting is generally free when you switch broadband. Your new provider will not usually charge to move your number; it is part of the standard switch. Some providers may charge a small fee, so it is worth asking up front, but many include it at no cost.

What can cost you is leaving your current contract early. If you are still mid-contract, you may face an early exit fee, typically calculated as your remaining monthly cost multiplied by the number of months left. The port is free, but the exit fee for cancelling early can be significant, so check your contract end date before you commit.

Remember too that you will pay for your new package going forward. Some providers include calls (for example, free weekend calls or free UK landline and mobile calls), while others charge extra for a calls package, often in the region of £5 to £10 a month for unlimited UK calls.

Keeping your number when you move home

Moving house is where keeping a number gets less certain, and it comes down to your telephone exchange and area code.

If you are staying in the same area, or moving within the same exchange area, you can usually keep your number. If you are moving to a different geographic area served by a different exchange, you will most likely need a new number with the new area code. For example, a London number (020) cannot be ported to Manchester (0161), because it is tied to the London exchange.

If you cannot take your number with you, one practical option is to set up call forwarding from the old number to your new number or mobile for a period, so you do not miss calls while you update your contacts.

What can go wrong, and how to protect your number

Most ports go through without a hitch. The problems that do occur are usually avoidable.

• Cancelling too early. The biggest risk. Never close your old account before the port is confirmed complete. If your broadband and phone are bundled with the same provider, cancelling the phone could also affect your internet, so be careful there too.
• Incorrect details. Mismatched names, addresses or numbers on the porting form are the most common cause of delay. Copy the account holder's name and address exactly as they appear on your latest bill.
• A port that fails or stalls. If a request fails, your provider will usually tell you why, most often a detail that does not match, and let you correct it and resubmit. Chase them if you have not had a confirmed go-live date within the expected window.
• A provider that does not offer landlines. Some smaller or mobile-broadband-only services do not support landline porting. Confirm this before you sign up if keeping your number matters to you.
• Older equipment. Telecare devices, security alarms and some older phones may need an adapter or replacement to work with digital voice. Most modern kit is fine, but check compatibility with the manufacturer or service provider before switching.

Frequently asked questions

Can I keep my number if I switch from BT to another provider? Yes. In most cases BT numbers, like others, can be ported to a new provider. Your new provider arranges it.

Does moving to full fibre or VoIP mean I lose my landline number? No. FTTP and VoIP change how your line is delivered, not your number. Your number ports across as normal.

Do I contact my old provider or the new one? The new one. Under One Touch Switch they manage the whole switch, including porting your number and cancelling your old service.

How long will I be without a phone? Usually only a few hours on the go-live date, not days.

What happens to my number during the PSTN switch-off? Nothing is lost. Your number carries over to digital voice. Only the underlying technology changes, with all Openreach PSTN users due to be migrated by 31 January 2027.

Can I port the number away again later? Yes. It is your number. You can move it to another provider whenever you like.