How to Keep Your Number When Changing Networks (PAC Guide)

Your phone number is part of your identity — banks, employers, family, and two-factor codes all hang off it. So when a better deal appears on another network, the fear of losing that number puts many people off switching. You do not have to choose between the deal and your number: in the UK and most countries, keeping your number when changing networks is a free, regulated right, and the whole move usually completes within one working day.

Quick Answer

To keep your number when changing networks, text “PAC” to 65075 from your old SIM (free, takes under a minute), give the PAC code to your new network when you sign up or within 30 days, and they will transfer your number — usually the next working day. Your old service ends automatically when the number moves, so never cancel the old contract yourself first.

What a PAC Code Is and How the System Works

PAC stands for Porting Authorisation Code. It is a nine-character code (three letters, six numbers) that authorises your new network to pull your number across from the old one. The process, called porting, is run between the networks themselves — you just supply the code and a transfer date. Since 2019, UK rules (“Text-to-Switch”) guarantee you can get a PAC by text without speaking to a retention team, and Ofcom’s switching guidance sets out the consumer protections, including the ban on charging for the old service after the switch date.

The same text-to-switch messages cover other situations too: texting “STAC” to 75075 gives a code that cancels your old service WITHOUT keeping the number, and texting “INFO” to 85075 shows your contract status and any exit fees before you commit.

Step by Step: Switching Networks and Keeping Your Number

1. Check your position: text INFO to 85075 to see whether you are out of contract or owe an early-exit fee.
2. Get your PAC: text PAC to 65075 from the number you want to keep. The code arrives by text, usually within a minute, and stays valid for 30 days.
3. Order your new SIM or phone and give the PAC during checkout, or afterwards in the new network’s app, website, or by phone. If you do not hand it over at sign-up, you can still provide it within the 30 days.
4. Pick your switch date — usually the next working day, or a later date you choose.
5. Keep using your old SIM until it loses signal on the switch day; then insert the new SIM. Your number may show a temporary number briefly — restart the phone and the ported number takes over.
6. Test calls and texts both ways, and check data works. Incoming calls route to the new SIM once the port completes, typically by the end of the switch day.

What Happens to Your Accounts and Apps

Because the number itself does not change, almost everything carries on untouched: WhatsApp keeps your account (it is tied to the number), banking apps keep working, and contacts still reach you. The transfer is about the network behind the number, not the number itself. Our guide on switching your number onto a new SIM with eSIM covers the same process when the new SIM is a digital eSIM rather than a physical card.

Timing, Costs, and Credit Checks

• Cost: porting is free. You may still owe an early termination charge if you leave a contract mid-term — the INFO text reveals this before you commit.
• Double billing: you cannot be charged by the old network after the switch date, and any overlap refund is automatic in most cases.
• Prepaid users: unused credit on the old network does NOT move with the number — spend it or accept the loss before switching.
• Credit checks: a new postpaid contract involves one; SIM-only and prepaid switches usually do not.
• Weekends: ports happen on working days, so a Friday request usually completes on Monday or Tuesday.

Common Mistakes to Avoid

• Cancelling the old contract yourself first. Cancellation ends the number — always let the port close the old account automatically.
• Letting the PAC expire. Codes last 30 days; if yours lapses, simply text for a fresh one.
• Throwing away the old SIM on switch morning. Keep it until the new SIM is live — the port can occasionally need a nudge, and your old line is your fallback.
• Porting on the day you desperately need the phone. There can be a few hours of patchy service mid-port; pick a quiet day.
• Forgetting eSIM activation details. If the new line is an eSIM, install its profile before the port completes to avoid a gap.

If Something Goes Wrong During the Port

Ports are routine, but occasionally a switch day passes with one-way audio, texts arriving but calls not (a “split port”), or the number not moving at all. Stay calm and methodical: restart the phone first, as many partial ports complete after a re-registration. If problems persist into the next working day, contact the NEW network — they own the port and can chase the old network on the shared porting system. Never ask the old network to “take the number back” mid-port; untangling a reversed port is far slower than finishing the original one.

Keep your paperwork until the first correct bill arrives: the PAC confirmation text, your switch date, and the final bill from the old network showing the account closed. If you are charged by the old network for any period after the switch date, that is against the rules and a single call with those dates normally produces a refund.

Special Cases: Family Accounts, Business Lines, and Landlines

Moving a number off a family or shared account may need the account holder’s involvement, since the PAC process assumes the requester controls the line. Business numbers port the same way technically, but contracts may carry different notice terms, so check before texting for the code. Landline numbers cannot move to mobile (or vice versa) through the mobile PAC system — they follow a separate process between fixed-line providers, though VoIP services blur the line for new setups.

Conclusion

Keeping your number is no longer a negotiation or a favour — it is a three-letter text away. Text PAC to 65075, hand the code to your new network, pick your day, and the number you have had for years moves with you, usually by the next working day. Follow the order in this guide — code first, cancellation never — and switching becomes the painless routine it should be.

Frequently Asked Questions

How long does it take for my number to transfer?

If you give your PAC before the daily cut-off (usually late afternoon), the number typically moves the next working day. During the switch there may be a short period where calls route inconsistently; by the end of the day everything settles on the new SIM.

Will I lose service during the switch?

Briefly, possibly. Your old SIM keeps working until the port begins, then your new SIM takes over with the same number. Most people notice nothing more than needing one phone restart; planning the switch for a quiet day removes any stress.

Can I keep my number if I owe money to my old network?

A network cannot refuse a PAC because of a debt, and the port will still go through — but the debt remains yours to pay, and unpaid final bills can affect your credit record. Settling the account keeps everything clean.

What if my new network forgets to use my PAC?

Contact them and provide the code again while it is still valid (30 days). Your number stays safely on the old network until a port is actually actioned, so nothing is lost — the old service continues meanwhile.

Can I move my number to a different person or a business account?

Changing the account holder is a separate process called a transfer of ownership, which both networks must agree to and usually requires the current holder’s authorisation. A PAC alone moves the number between your own accounts, keeping you as the holder.