Phone help
How to keep your phone number when you switch provider
Number porting is moving your phone number from one provider to another. On a mobile it takes one text and one working day. On a landline the new provider does it for you under One Touch Switch. On an 0800 or 03 number there is a letter to sign. Each one is below, with timings and the mistakes that leave people with a dead number, from Ofcom and the networks’ own help pages.
The basics
What number porting is
The right to take your number with you is yours. Ofcom calls number portability a regulated facility that lets customers keep their numbers when changing provider, with the rules in General Condition B3 (Number Portability) and C7 (Switching) under the Communications Act 2003 (Ofcom, number portability). A provider can charge what the contract says when you leave early; it cannot keep the number.
Porting is only for people who are leaving. If you want calls to ring somewhere else, that is a divert: a code on your own phone that changes nothing about who holds the number (see what call forwarding is and call divert codes). If you cancelled without asking to keep the number, the new provider can still port it for free within one month of cancelling, on mobile and landline alike (Ofcom, switching mobile; Ofcom, switching landline).
Mobiles
Porting a mobile number: PAC, STAC and Text to Switch
Three free texts, sent from the phone whose number is on the account, cover it, and you never speak to the network you are leaving (Ofcom):
- PAC to 65075 to keep your number (Porting Authorisation Code).
- STAC to 75075 to leave without it (Service Termination Authorisation Code).
- INFO to 85075 to see whether you are in contract and what leaving costs.
The reply must come within a minute, with any early termination charge or remaining pay as you go credit alongside. A PAC is three letters then six numbers, a STAC the reverse (Vodafone Business), and both last 30 days.
The code does nothing until the new network has it
Vodafone puts it plainly: your plan does not end when you get the PAC, and you must give it to your new network for anything to happen (Vodafone). Handing it over is what closes the old account, on the date the two networks agree (Three).
The one working day rule
Once the new provider has your PAC they must complete the switch within one working day, with compensation if it takes longer (Ofcom). O2 and Three both say a code received after 5pm, at a weekend or on a bank holiday moves on the second working day; on the day, O2 says it usually happens by 4pm and can take until 10pm (O2; Three). Two things stop the clock: Three needs the new SIM activated (in a phone, showing signal) by 5pm the working day before, and you must be in the UK on the day.
Early termination charges, eSIMs and business accounts
A PAC moves the number; it does not cancel what you owe. Inside the contract term an early termination fee may apply, and the INFO text shows the figure before you commit (Vodafone). An eSIM is still a SIM, so a port on to one follows the same steps; moving to an eSIM with your current provider is a SIM swap done from your account, since a PAC is only for changing network (O2; Three).
The text service only works for an account with one number. With two to 24 numbers you ask online or by phone, and the code must come within two hours by phone or two working days online (Ofcom, switching for businesses); EE Business, for one, emails it within two working days (EE Business).
Landlines
Porting a landline number: One Touch Switch
Landline and broadband switching changed on 12 September 2024, when Ofcom’s One Touch Switch went live across every network, cable and full fibre included (Ofcom, simpler switching is here). The gaining provider does the work: you give them your address and current provider, the old provider sends you the leaving information with any early termination charge, and if you go ahead the new provider runs the switch on your chosen date (Ofcom, one year on). You cannot be charged for a notice period beyond the switch date, and any loss of service must be under one working day.
Keeping the number is a question the new provider asks at the start, and saying yes is all the old provider needs to hear from you (Ofcom). Sky says you keep it most of the time if you give it when ordering, except that anyone coming from NOW Broadband gets a new number (Sky). One limit: a landline number belongs to an exchange, and BT says a move to a different exchange cannot keep the number because the dialling code changes (BT).
Porting a landline number to a mobile, or to an internet phone service
There is no PAC for a landline, and a landline number cannot become a mobile number: Ofcom’s numbering guide says 01 and 02 numbers relate to specific locations and 07 numbers are mobiles (Ofcom, call costs). “Port my landline to my mobile” means one of two things: a divert, so unanswered landline calls go to the mobile, which is a code and not a port; or a real port of the 01 or 02 number to a provider that carries calls over the internet, so it rings an app on the mobile, a desk phone or an answering service. In that port only the number moves, and calls are routed onward by the range holder, the provider Ofcom first allocated the number to (Virgin Media Business).
The digital switch-off and your number
The copper telephone network, the PSTN, is being retired. Ofcom’s guide, updated August 2026, says BT plans to retire its old landline network by 31 January 2027, while Virgin Media O2 and KCOM have not set dates for their own networks (Ofcom, your landline is going digital), though Virgin Media said in July 2025 it aimed to finish within 18 months (Virgin Media).
Ofcom says you keep your number; the phone plugs into the router instead of the wall socket (Ofcom). Nothing is ported, and a number on a digital line can still move through One Touch Switch. The danger is elsewhere: BT warns that if you take broadband without a landline you lose the number and cannot get it back (BT). If the number is on your van, keep a phone service attached to it, even the cheapest.
Business numbers
Porting 0800, 0808, 03 and other business numbers
Freephone 0800 and 0808 numbers are free to call from consumer phones, and 03 numbers cost no more than an 01 or 02 call (Ofcom; see our guide to 0333 numbers). All of them port, with the same paperwork as an 01 or 02 number: a Letter of Authority on your headed paper, on one page, signed by someone with authority in the business, dated, and saved as a PDF because the losing provider will not accept an editable file. The losing provider accepts or rejects it with a reason; once accepted you get a date, test calls are made beforehand, and the port goes through on the day (Virgin Media Business).
What a “ported-in” number means on an internet phone or answering service
It means the range holder is routing calls for your number onward to the provider that holds it now (Virgin Media Business). So the provider you port to needs an agreement with your number’s range holder; ask before signing. If that provider closes, or you leave it, you port again with another letter. Once there, the number can be pointed at a mobile app, an office handset or an answering service without moving again.
The problems that stop a port
- The number is tied to a bundle. Ofcom says moving the landline while keeping broadband with the same provider can affect the broadband linked to it (Ofcom). Ask before the port goes in.
- The number is in someone else’s name. A number a previous owner, landlord or former partner took out stays theirs until the account is transferred into yours. Sort the account, then port.
- Postcode or account name does not match. One Touch Switch matches your details against the old provider’s records, and Ofcom said at launch that a minority of switches fail on that matching (Ofcom); Virgin Media says that if it cannot find your account you must contact the old provider yourself (Virgin Media). Copy the details from a recent bill, not from memory.
Timings
How long number porting takes, by type
| Port | Who starts it | Code or process | Time | What can go wrong |
|---|---|---|---|---|
| Mobile, keeping the number | You, with a code from the old network | PAC: text PAC to 65075 | One working day; two if the code lands after 5pm or at a weekend | Code expired, new SIM not activated, you are abroad |
| Mobile, leaving the number | You, with a code from the old network | STAC: text STAC to 75075 | Old account closed within 24 hours of your chosen date | Old account keeps billing if the code is never used |
| Landline, with or without broadband | The new provider (One Touch Switch) | No code: details matched against the old provider’s records | Your chosen date; loss of service under one working day | Details do not match, or a new address on another exchange |
| Landline number to an internet phone service | The new provider, with a letter you sign | Geographic port (01 and 02) | A date agreed with the provider | Letter not on headed paper or signed by the wrong person, old provider rejects it |
| 03, 0800 or other 08 number | The new provider, with a letter you sign | Non-geographic port | A date agreed with the provider | Same paperwork problems |
| Copper landline to digital landline | Your provider writes with a date | Nothing to request; the phone plugs into the router | BT plans to retire its old network by 31 January 2027 | Ignore the letter and the socket stops working |
Before you port
A checklist before you move a number
- Text INFO to 85075 (mobile) or read the leaving information (landline), so you know the early termination charge first.
- Check whose name the account is in. If it is not yours, transfer it first.
- Copy the account name, address, postcode and account number from a recent bill.
- List what else is on the line (broadband, TV, card machine, care alarm) and ask what happens to each.
- Sign up with the new provider, then hand over the code or the letter. A PAC expires after 30 days.
- Leave your divert on the old service until the new one is live, then set it again; diverts do not travel with the number.
For businesses
You do not need to port your number to use While You Work
Most people who land here are not leaving anyone; they have a number on the van and a phone that rings while they are under a sink or mid-lesson. That needs a divert, not a port. You keep your number on whatever network it is on, we give you a number to divert to, and you set a no-answer divert with one code from the call divert codes page. Your phone rings for 20 seconds as usual; if you cannot get to it, a British-sounding receptionist answers in your business name, takes the caller’s name, number and what they need, and emails it to you within a minute. If you cancel, you dial the cancel code and the divert is gone.
If you are also changing provider, port first, wait for the number to go live, then set the divert again. See how the call answering service works, or what the AI receptionist will and will not do in your name.
Questions
Number porting FAQs
What is a PAC code?
A Porting Authorisation Code: the code your mobile network gives you so a new network can take your number. Text PAC to 65075 from the phone whose number you want to keep and give the code to the new network. It lasts 30 days.
How long does it take to port a mobile number?
One working day from the new provider getting your PAC, under Ofcom’s rules. O2 and Three both say a code received after 5pm, at a weekend or on a bank holiday moves on the second working day.
Can I keep my number if I am still in contract?
Yes. The number moves whether or not the contract has ended; the old provider must send any early termination charge with the PAC. Text INFO to 85075 to see the figure first.
What is One Touch Switch?
How landline and broadband switching has worked since September 2024. You contact only the provider you want to join; your current provider sends the leaving information and the new one manages the switch, asking at the start whether you want to keep your number.
Can I port my landline number to my mobile?
Not as a mobile number: 01 and 02 numbers relate to places and 07 numbers are mobiles. You can divert the landline to the mobile, which needs no port, or port the landline number to an internet phone service that rings an app on the mobile.
Do I need to port my number to use an answering service?
No. With While You Work your number stays with your network. You set a divert so calls you do not answer come to us, and we answer in your business name. A port is only for people leaving their provider.
Sources
All pages read on 31 October 2026. Help pages change, so check the latest version.
- Ofcom: Switching mobile phone provider, Switching mobile (advice for businesses), Switching landline provider, Simpler and quicker broadband switching is here, 1.6 million Brits hit switch, Your landline is going digital, Number portability and How much does a phone call really cost?
- EE Business: How to switch from EE to a new provider
- O2: How to keep your mobile number
- Vodafone: How do I get a PAC? and What are PAC, STAC and INFO codes?
- Three: Help with switching to Three
- BT: Switch to BT with One Touch Switch and Keeping my phone number when I move home
- Sky: Switching to Sky Broadband and Talk
- Virgin Media: Switch to Virgin Media and What’s happening to landlines?
- Virgin Media Business: Landline geographic and non-geographic number porting
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