What is a PAC code and how to get one (keep your number)

A PAC code — short for Porting Authorisation Code — is the nine-character key that lets you move your mobile number from one UK network to another without changing it. If you have spent years giving the same 07 number to friends, family, your bank and every delivery driver in the country, the PAC is what protects it when you switch provider. Since 1 July 2019, getting one has been deliberately painless: you text a single word and the code arrives within a minute, free of charge, under rules set by Ofcom. This guide explains exactly what a PAC code is, how to get one from any UK network, how long it lasts, what the alternative STAC code does, and how the whole switch actually plays out day by day.

#What a PAC code actually is

Every UK mobile number is, technically, allocated by Ofcom to an original 'range holder' network — that is the company that was first given the block of numbers your number sits in. But because you are allowed to keep your number when you switch, the network that *physically* serves your SIM today can be completely different from the range holder. A PAC code is the mechanism that performs that hand-over cleanly. When you give a PAC to your new network, you are authorising them to 'port in' your number: to tell the industry's central routing systems that calls and texts to your number should now land on their SIM instead of your old one.

The code itself looks something like ABC123456 — three letters followed by six digits. It is unique to your number and your request, and it expires, so a PAC you generated last month will not work today. It is not a password for your account and it is not your PUK; it exists for one job only, which is to move the number.

The reason any of this matters to people who land on this site is simple: your mobile number is an identity. It is tied to your banking app's two-factor login, your WhatsApp account, your delivery notifications and a hundred password resets. Losing it during a botched switch is a genuine hassle, which is exactly why the PAC process exists and why Ofcom forced every network onto the same simple text-message system.

#How to get a PAC code (text PAC to 65075)

Since 1 July 2019, every UK mobile network must let you request a PAC by text. You do not have to phone a retention team, sit through a winback offer, or explain why you are leaving. The process is identical on EE, O2, Vodafone, Three and every network that piggybacks on them (Giffgaff, Tesco Mobile, Sky Mobile, Smarty, Voxi, Lebara, iD Mobile, Lyca and the rest).

1. 1

   Text the word PAC to 65075

   From the mobile you want to keep, send a text containing just the word PAC to 65075. It is free and works even if you have run out of credit or allowance.

2. 2

   Read the reply carefully

   Within 60 seconds you receive a text with your PAC code plus any charges for leaving — early-termination fees, outstanding handset instalments, or your remaining notice period. The code is valid for 30 days.

3. 3

   Take out your new plan and hand over the PAC

   Sign up with your new network and give them the PAC when prompted. Do not cancel your old contract yourself — the port handles closure automatically once it completes.

4. 4

   Wait for the switch — next working day

   Your number moves to the new SIM by the next working day. There is usually only a short window (often a few minutes) where service briefly drops as the number cuts over.

If you would rather not text, you can still request a PAC in your network's app or by calling them, but the text route is the fastest and is the one Ofcom designed to be friction-free. The 65075 short code is the same across all networks — you can read more about how UK short codes like this are reserved and operated.

#PAC vs STAC: keep your number or leave clean

There are two switching codes, and choosing the wrong one is the single most common mistake people make.

Use a PAC if you want to keep the number — which is almost everyone. Use a STAC only when you are genuinely finished with a number, for example closing a second line or a child's old SIM. If you request a STAC and then change your mind, the number is gone, so be sure. Either way, the request text also itemises any money you still owe, which prevents the nasty surprise of a final bill you did not expect.

#Getting a PAC from each major network

The text-to-65075 method is universal, but people often search specifically for their own provider, so here is the network-by-network picture. In every case the text is the fastest route; the app and phone options exist as fallbacks.

EE PAC code

Text PAC to 65075, or find it in the EE app under your plan settings, or call 150 from an EE phone. EE is the largest UK network and the range holder for a very large share of 07 blocks — see which prefixes sit with which operator in our mobile networks by prefix guide.

O2 PAC code

Text PAC to 65075, use the My O2 app, or call 202 from an O2 handset. O2 also hosts Giffgaff, Tesco Mobile, Sky Mobile and Lycamobile, and the text route works identically on all of them.

Vodafone PAC code

Text PAC to 65075, request it in the My Vodafone app, or call 191. Voxi and Lebara run on Vodafone and follow the same process.

Three PAC code

Text PAC to 65075, use the Three app, or call 333. Smarty and iD Mobile (which uses Three's network) also honour the text request.

#How long a PAC code lasts and what happens if it expires

A PAC code is valid for 30 calendar days from the moment it is generated. If you do not use it within that window, it simply lapses and your number stays exactly where it is — nothing breaks, you have not started any switch, and you can request a fresh code whenever you are ready. There is no limit on how many times you can ask for a PAC, so if you generated one while comparing deals and it expired, just text 65075 again.

Because the code only triggers the move when you hand it to a new network, requesting a PAC is completely safe as a way of *seeing* what leaving would cost. The reply text shows your exit charges; if they are higher than you expected you can simply do nothing and let the code expire.

#The switch timeline, day by day

Ofcom's rules require the port to complete by the next working day after your new provider receives the PAC. In practice the experience looks like this:

1. Day 0 — request: You text PAC to 65075 and get your code plus any charges within a minute.
2. Day 0 — sign up: You take out the new plan and give the new network your PAC. They order the port.
3. Next working day — cutover: Your number moves to the new SIM. Expect a brief service gap (often minutes) during the switch.
4. After the switch: Your old contract closes automatically. A final bill may arrive covering usage up to the switch and any exit fees.

Weekends and bank holidays are not working days, so a PAC handed over on a Friday afternoon typically completes on the following Monday. Keep your old SIM in the phone until the new one is live, and do not cancel the old plan yourself — doing so can actually break the port.

#What a PAC does not do

It is worth being clear about the limits of porting, because a few things commonly trip people up:

• It does not transfer your contract or allowances. You start fresh on the new network's plan; only the number moves.
• It does not move your credit balance on pay-as-you-go. Spend down or write off any remaining PAYG credit before you switch.
• It does not migrate your texts, contacts or voicemails. Back those up separately — contacts via your Google or Apple account, for example.
• It does not change your number's underlying range holder in Ofcom's data. The number can still *read* as an original network even after years on another — which is exactly why a reverse lookup shows the range holder, not necessarily today's carrier.
• It does not protect you from losing the number if you let the new contract lapse. Once ported, the number lives with whoever currently serves it.

That last point about range holders is the reason this guide lives on a number-lookup site. When you try to identify who called you, the data tells you which network *originally* held the number, not which one serves it now — because a PAC may have moved it. Understanding that gap is the whole point of our number portability explainer.

#Which networks host which: PAC works the same on all of them

The UK has four networks that actually own infrastructure — EE, O2, Vodafone and Three — and a long list of 'virtual' operators (MVNOs) that rent capacity from them. People often worry the switching rules are different on a budget SIM brand, but they are not: every one of these must honour the text-to-65075 PAC request and the next-working-day port. The table below shows who runs on whom, which is also useful context when you are trying to work out who actually carries a number you are checking.

This matters for number identification as much as for switching. Because a number can be ported across any of these, the network that originally held it (the range holder shown in Ofcom data) is frequently not the network serving it today. Our guide to UK mobile networks by prefix explains how the 07 ranges were originally carved up, and why a 'this is a Three number' label can be years out of date.

#Switching when your phone is lost, broken or stolen

The text-to-65075 method assumes you can send a text from the number you are moving. If the handset is lost, stolen or dead, you obviously cannot — but you can still get a PAC. Log in to your network's online account or app from another device and request the code there, or phone the network's customer line and ask. They will verify your identity through your account security rather than the SIM. If the phone was stolen, report it to the network so they can bar the handset (by IMEI) and issue a replacement SIM, then request the PAC once you have access again.

This is also a good moment to flag a security point: your mobile number is the second factor for a lot of accounts, so a criminal who manages to port your number away from you can intercept banking and email reset codes. This attack — sometimes called SIM-swap or port-out fraud — is why networks now apply extra checks to porting requests, and why you should treat any unexpected 'your PAC has been requested' text as a red flag worth phoning your network about immediately.

#eSIM, dual-SIM and keeping a number on a new handset

Switching network and switching handset are two separate things, and a PAC only deals with the first. If you are also moving to a new phone, your number simply lands on whatever SIM — physical or eSIM — the new network issues. Most major networks now offer eSIM, so you may complete a switch entirely digitally: request the PAC, sign up online, and activate an eSIM by scanning a QR code, with the number porting onto it by the next working day.

Dual-SIM phones add a useful trick. You can keep your old SIM active in slot one while you set up and test the new network's SIM in slot two, only handing over the PAC once you are happy with coverage. That removes almost all of the risk from switching, because you never have a moment without a working line. If you want to sanity-check that a number is a valid, dialable UK mobile before relying on it, our validate a UK mobile number tool walks through the format rules.

#When a port goes wrong, and how to fix it

The overwhelming majority of switches are uneventful, but ports can occasionally stall. The usual causes and fixes are predictable:

• You cancelled the old contract yourself. This is the classic mistake — cancelling breaks the link the port needs. Never cancel; let the switch close the old line.
• A name or address mismatch. The details on your new account must match the old one closely enough for the networks to agree it is the same person. Correct any typo and the port usually clears.
• The PAC expired. If more than 30 days passed, just text 65075 for a fresh code and hand the new one over.
• A bar on the number. A lost-phone bar or unpaid balance can block a port. Clear the balance or lift the bar first.
• A weekend or bank holiday. Remember these are not working days, so a Friday request can complete on Monday rather than Saturday.

If a port has not completed within one working day and none of the above applies, your new network should chase it for you — porting disputes are their responsibility to resolve under Ofcom rules, not yours. Keep a note of the date and time you handed over the PAC in case you need to escalate.

#Why this is on a number-lookup site

WhoCalledLookup exists to answer one question — who is calling me from this number — and PAC codes are central to why that question is harder than it looks. Number portability means the tidy idea that 'an 07 number belongs to network X' broke down years ago. Tens of millions of UK numbers have been ported at least once, so the prefix and the original range holder are clues, not answers. When you run a lookup, we show the range holder from official Ofcom data and layer an internet check on top, precisely because the carrier today may differ from the one that first held the block. If the call was unwanted, our guides on spotting scam numbers and who called me take it from there.

#Bottom line

A PAC code is the simple, free, 30-day key that lets you change UK mobile network while keeping the number everyone already has for you. Text PAC to 65075, read the charges, hand the code to your new provider, and the number moves by the next working day. Use STAC only if you genuinely want to abandon the number. Keep your old SIM in until the switch lands, never cancel the old plan yourself, and treat any PAC request you did not make as a security alert. And remember that once a number has been ported, it no longer cleanly maps to its original network — so if an unfamiliar 07 number rings you, look it up rather than assuming the prefix tells you who is calling.