Keep your business mobile number when you switch

How keeping your number works

Moving a mobile number from one network to another is called porting. Your business keeps the number; only the network behind it changes. The process is set by Ofcom, the UK communications regulator, and every UK mobile provider has to follow it, whether you are leaving EE Business, Three Business, O2 Business, Vodafone Business or a smaller provider.

The process is driven by you as the customer, not by the network you are leaving. You ask your current provider for a code, give that code to the new provider, and the new provider arranges the move. You do not have to talk your old network into letting you go, and you do not have to cancel the old service yourself: the switch does that.

There are two codes, and which one you need depends on whether you want to keep the number:

• PAC (Porting Authorisation Code): keeps your existing number and moves it to the new network. See our guide to the PAC code.
• STAC (Service Termination Authorisation Code): ends the old service without keeping the number, so you take a new number on the new network. See our guide to the STAC code.

Most businesses want the PAC for lines that customers ring, and a STAC for spare or legacy lines that nobody relies on any more. You can mix the two across a team.

PAC or STAC: which code do you need?

Requesting either code by text is free, and Ofcom says your provider must send information about any early termination charge with the code, so you can see what leaving will cost before you commit. Ofcom also describes a separate text service, INFO to 85075, for checking whether you are still in contract without requesting a code at all, and EE Business and O2 Business both publish it for business customers.

Ofcom's mobile switching rules

Ofcom calls the process Text to Switch. Its guide to switching mobile provider is written for everyone, and the business networks' own help pages describe the same codes for business accounts. Ofcom's main points are:

• One number: text PAC to 65075 (or STAC to 75075). Ofcom says your current provider must reply with the code within one minute. You can also ask by phone or on the provider's website.
• More than one number on the account: Ofcom says you need to ask by phone or on the provider's website rather than by text. Business networks publish their own routes for larger accounts, set out in our guide to porting multiple mobile numbers.
• Exit costs up front: the provider must send details of any early termination charge with the code.
• Validity: a PAC or STAC is valid for 30 days.
• Speed: Ofcom says the new provider must complete the switch within one working day, and any loss of service must not last longer than one working day.
• Notice periods: Ofcom says your old provider must not charge you for any notice period after the switching date, so you do not pay twice once you have moved.
• Compensation: Ofcom says providers may need to compensate you if the switch is delayed or you are left without service for longer than allowed.
• After cancelling: Ofcom says that in most cases you can still transfer your old number to a new service within one month of cancelling.

These are Ofcom's rules for every provider, and they give businesses real leverage: you control the timing, you see exit costs up front, and the old network cannot hold your numbers back.

Step by step: keeping your number

1. Check your contract. Find out whether each line is still in a minimum term and what leaving early would cost. The code will come with that information, or you can text INFO to 85075 first.
2. Choose the new plan. Pick the network and business SIM only plan that suit each user, and decide between a physical SIM and an eSIM SIM only plan.
3. Check the phones. Ofcom says providers can no longer sell locked phones, but an older handset may still be locked to the old network, and EE Business notes you may need to unlock a device before its SIM will work. For eSIM, the phone must support it.
4. Request the PAC. Text PAC to 65075 from the number for a single line, or use your provider's online account or phone line for several numbers.
5. Give the PAC to the new provider with the switch date you want, inside the 30 days the code is valid.
6. Activate the new SIM before switch day. Three Business recommends this so you know the new SIM works before the number moves.
7. On switch day, the old SIM loses signal and the new one takes over the number.

If you are moving several people, do this as one planned exercise rather than line by line. Our fleet SIM cards guide covers keeping a record of which number and SIM belongs to whom.

What happens on switch day

The networks describe switch day in similar terms. The old SIM stops working and the new SIM picks up your number. A few points from their own help pages are worth knowing in advance:

• Expect a short gap. It is normal to lose service for a short time while a number transfers. Three Business, for example, says the switch may take until midnight to complete, with service split across both SIMs for a while.
• Keep both SIMs handy. When the old SIM loses signal, put the new one in (or switch to the eSIM). If there is no signal, Three Business suggests restarting the phone every couple of hours until it connects.
• iPhone users may need to update the number. Three Business says iPhone users need to update their number manually in the device settings once the transfer has completed.
• Be in the UK. O2 Business and Three Business both say you need to be in the UK, on the network, for the switch to complete.
• Billing stops at the old provider. EE Business explains that because you gave a PAC or STAC, the old provider should stop billing at the same time the service moves.

Changing your mind is possible up to a point. Three Business says a transfer can be changed or cancelled until 5pm on the working day before it is due, and describes that cut-off as an industry-wide deadline.

Mobile numbers, landlines and VoIP

Everything on this page is about mobile numbers: the numbers on SIMs and eSIMs. Landline and VoIP numbers move between providers through a different process with different rules. If you are also moving your office phone numbers, for example to a cloud phone system, see number porting for landline and VoIP numbers on our cloud phone site.

Moving to a new network is also a good time to think about the phones themselves. With the airtime on SIM only, you can buy any new phones separately and refresh them when it suits you; our sister site covers business mobile devices and device management, and our guide to buying business phones separately explains the approach.

How we help

Switching networks is simple for one person and fiddly for twenty. We can take the admin off your hands and help the move go smoothly:

• Plan the move: list your numbers, check contract end dates and early termination information, and choose which lines need a PAC and which a STAC
• Match plans to people: suggest the right business SIM only plan and network for each user, on EE Business or Three Business, or on O2 Business or Vodafone Business
• Handle the codes: help you request PACs and STACs and give them to the new network with a sensible switch date
• Prepare the SIMs: help you get physical SIMs or eSIMs activated and tested before switch day
• Brief your team: what to expect on switch day, when to swap SIMs and what to update afterwards

Timings and what each network can offer are confirmed at quote. Contact us with the number of lines you want to move and we will suggest how to approach it.