Can I keep my business phone number if I change provider?

The short answer: yes, in almost all cases. Moving a number from one provider to another is called number porting, and it works for UK landline numbers, 0800 and 03 numbers, and mobiles. The one big rule: don't cancel your old service until the number has moved, or you risk losing it.

What numbers can be moved

Most business numbers can be ported, including:

• Geographic landline numbers, the ones starting 01 or 02.
• Non-geographic numbers such as 0800, 0808, 0330, 0333 and 0345.
• Ranges of numbers on ISDN lines or older phone systems, including direct dial numbers for individual people.
• Mobile numbers.

A landline number is tied to a geographic area, so if you're moving a long way, check with your new provider that it can keep the number working where you're going. With cloud phone systems this is usually fine.

How porting works

The good news is that your new provider does most of the work. You don't normally need to ask your old provider for anything for landline numbers.

1. Choose your new provider and tell them which numbers you want to bring.
2. Give them your current account details exactly as they appear on your bill. That means the account holder's name, the installation address and postcode, your account number and the main billing number. Mismatches are the most common reason ports get rejected.
3. Sign a Letter of Authority (LOA) if they ask for one. It's a simple form confirming you own the numbers and want them moved.
4. Your new provider submits the request to your old provider and agrees a date.
5. Set up the new system first. Phones, apps, call routing and greetings should be ready and tested before the switch day.
6. On the day, the numbers switch over. Calls start arriving on your new system, usually with little or no disruption.

How long it takes

It varies by number type and provider:

• A single landline number typically takes a few working days to a couple of weeks.
• Multi-line numbers and ISDN ranges usually take longer, as there's more to check.
• Non-geographic numbers like 0800 and 03 can take a little longer again, depending on who supplies them.

If a port is rejected, it's nearly always because some detail didn't match the old account. Your new provider will tell you what to fix and resubmit, which adds time. Starting early helps, especially if you're also dealing with the PSTN switch-off.

Mistakes to avoid

• Cancelling your old service first. If the line or account is closed before the port completes, the number can be lost for good. Let the port happen, then tidy up anything left.
• Forgetting other services on the same account. Porting a number usually ends that number's service with your old provider, but broadband, extra lines or rental equipment on the same account may keep running and keep billing. Check your next bill.
• Ignoring your contract. Check your contract end date and notice period with your old provider before you move. Leaving early can mean exit fees, and some contracts need written notice.
• Guessing the details. Copy them from a recent bill rather than from memory.

Mobile numbers

Mobiles work differently and are simpler. To keep your number, text PAC to 65075 from the phone (or ask your provider for it). You get a PAC code back by text. Give that to your new mobile provider, and the number usually moves within one working day. For several business mobiles on one account, the account holder may need to request the codes.

Common questions

Will I lose calls while the number is moving?

Usually not, or only for a short time on the day of the switch. Having your new system set up and tested before the port date makes it smooth.

Can I move my number to a cloud phone system?

Yes. Moving existing numbers onto a VoIP system is very common, and you keep the same number your customers already know. See What is VoIP, and is it right for a small business?

Can my old provider refuse to release my number?

Generally no. Your number can be ported even if you're unhappy with your old provider. They can still charge you anything owed under your contract, so check for exit fees, but they shouldn't block the move.

What if the number is in someone else's name?

The port needs to come from the account holder. If the account is in a previous owner's or a former director's name, sort that out with your old provider first, as ports with the wrong name are rejected.