The Short Answer: How to Switch Mobile Network and Keep Your Number in the UK
To switch mobile network and keep your number in the UK, text PAC to 65075. Your current provider must send your PAC (Porting Authorisation Code) by text within seconds, along with details of any exit fees. Give that code to your new provider when you sign up — they handle the rest. Your number ports across, usually by 11am the next working day, and your old contract closes automatically. You do not need to cancel first. The whole process can be completed in under ten minutes if you switch to an eSIM provider, because there is no physical SIM card to wait for.
Switching Mobile Provider in the UK Is Easier Than You Think
Most people stay with a provider they are not happy with simply because switching feels complicated. It is not. The entire process — getting your PAC code, porting your number, activating a new SIM — can take less time than your lunch break. The real question is not how to switch. It is what you are switching to.
This guide covers everything: PAC codes, timing, mid-contract switches, and why choosing a multi-network eSIM means you will probably never need to switch again.
How to Get Your PAC Code
Your PAC (Porting Authorisation Code) is the key to taking your mobile number with you when you leave a provider. Under Ofcom rules, your current provider must give it to you immediately — and they cannot make it difficult.
The fastest way: text PAC to 65075.
You will receive your PAC code by text within seconds, along with information about any early termination fees. That is it. No phone calls, no retentions team, no awkward conversation.
Alternatively, you can:
- Call your provider and ask for it directly
- Log into your account online (some providers offer this)
- Visit a store in person
The text method is by far the quickest. Once you have your PAC code, it is valid for 30 days — so you have plenty of time to get your new SIM sorted before using it.
Do You Need to Cancel Before Switching?
No. This is one of the most common misconceptions about switching mobile provider in the UK. You do not need to cancel your current contract before you switch.
When you give your PAC code to your new provider, they handle the port for you. Your old contract is automatically terminated on the date your number transfers. If you are out of contract, there is nothing more to do. If you are mid-contract, your old provider may charge an early termination fee — but you do not need to cancel separately.
Cancelling before you switch is actually the wrong move. You would lose your number in the process.
Can You Switch Mobile Provider Mid-Contract?
Yes — but it may cost you. If you are still within a minimum term, your provider can charge you for the remaining months. This is called an early termination fee (ETF).
Before switching mid-contract, it is worth doing the maths:
- Check your remaining months — log into your account or call your provider
- Get your PAC code via text — the reply will include any ETF amount
- Compare the ETF against your potential savings — if your new plan is significantly cheaper, the ETF might pay for itself quickly
If the numbers do not stack up, you can always set a reminder for your contract end date and switch then. Most providers are required to notify you when your minimum term is ending — so keep an eye on those messages.
One thing worth knowing: SIM-only plans are almost always rolling monthly contracts with no minimum term. Switching mobile provider on a SIM-only deal is genuinely instant — text PAC to 65075, sign up with your new provider, and you are done.
What Is the Fastest Way to Switch?
The traditional switching process looks like this:
- Text PAC to 65075
- Sign up with new provider
- Give them your PAC code
- Wait for a physical SIM to arrive (2–5 days)
- Activate the SIM
- Your number ports over (usually by 11am on a working day)
The bottleneck? Waiting for a physical SIM in the post.
With an eSIM provider, steps 4 and 5 collapse into one. You scan a QR code, your eSIM activates in minutes, and you are ready to go — no envelope, no plastic card, no waiting around.
Fuse Mobile is a UK multi-network eSIM that connects to all four UK networks — EE, Three, Vodafone, and O2 — so your phone automatically uses whichever signal is strongest wherever you are. You can activate your Fuse eSIM via QR code in minutes, then give your PAC code during sign-up to bring your existing number across.
For anyone switching on a SIM-only basis, this is genuinely the fastest route available.
Why Most Switching Guides Miss the Point
Comparison sites do a solid job of explaining how to switch. What they rarely address is the structural problem with the UK mobile market: most providers lock you to a single network.
Four UK networks, one eSIM. No contract.
Get connected to all four UK networks and never worry about signal again.
If you switch from one provider to another and both run on the same network, you have changed your contract but not your coverage. You are still subject to the same dead zones, the same congestion, the same signal gaps on the commute.
The UK has four mobile networks: EE, Three, Vodafone, and O2. Each one has different strengths depending on where you live, work, and travel. No single network covers everywhere perfectly — which is why being tied to just one is a structural disadvantage.
Multi-network coverage changes that entirely. Instead of picking the network you think is best and hoping for the best, your phone automatically connects to whichever of the four networks has the strongest signal at any given moment. It is a fundamentally different experience.
Switching to Fuse: What Makes It Different
Fuse Mobile is not another single-network provider with a slightly different price tag. It is built on all four UK networks simultaneously, which means the coverage question is answered before you even ask it.
Here is what switching to Fuse looks like in practice:
- Sign up and choose a plan — rolling monthly, no contract
- Scan the QR code — your eSIM activates in minutes
- Enter your PAC code — your existing number ports across
- Done — your phone now connects to EE, Three, Vodafone, and O2 automatically
There is no waiting for a SIM card. No contract to sign. No minimum term to worry about. If it is not right for you, cancel anytime.
Which Fuse Plan Is Right for You?
Fuse keeps things simple with three plans:
| Plan | Data | Price | Roaming |
|---|---|---|---|
| Spark | 5GB | £5.99/month | UK only |
| Pulse | 10GB | £9.99/month | 130+ countries |
| Surge | 15GB | £14.99/month | 130+ countries |
All plans are rolling monthly with no contract. Roaming is included on Pulse and Surge across 130+ countries. Fuse is the only UK provider combining all-four-network coverage with built-in international roaming at this price point.
Not sure which to go for? You can compare plans and see full details before committing to anything.
What About Keeping Your Number?
Your number is yours. Ofcom rules make this clear — no provider can hold it hostage, delay your PAC code, or make porting unnecessarily difficult.
When you switch to Fuse, you give your PAC code during the sign-up process. The port typically completes by 11am on the next working day. During the brief window when the port is in progress, you may lose service for a short period — usually less than an hour. It is worth planning for this if you are expecting important calls.
A few practical tips for a smooth number port:
- Do not cancel your old SIM before porting — you will lose the number
- Port on a weekday — ports do not process on weekends or bank holidays
- Keep your old SIM active until the port completes, just in case
- Your PAC code lasts 30 days — no rush, but do not forget about it
Is Switching Mid-Contract Worth It?
It depends on your situation. If you are paying over the odds for a plan that does not serve you well — poor coverage, too little data, a price that has crept up — the maths often favour switching even with an ETF.
A useful rule of thumb: if your monthly saving on the new plan exceeds your ETF divided by the number of months remaining, you will break even before your old contract would have ended anyway. After that, you are ahead.
If you are on a SIM-only rolling contract, there is no ETF at all. Switching mobile provider on SIM-only is as simple as it gets — text PAC to 65075 and you are halfway there.
Want to see how Fuse compares to what you are currently paying? See how Fuse works and decide for yourself.
FAQ
How do I switch mobile network and keep my number in the UK?
Text PAC to 65075 from your current phone. Your provider must reply within seconds with your PAC code and details of any exit fees. Give that code to your new provider when you sign up — they handle the number port for you. Your old contract closes automatically on the day your number transfers, which is usually by 11am the next working day.
Do I need to cancel my current contract before switching?
No — and you should not. Cancelling before you port will cause you to lose your number permanently. Give your PAC code to your new provider and they will manage the cancellation as part of the switch process.
Can I switch mobile provider mid-contract?
Yes. Your provider may charge an early termination fee for the months remaining on your minimum term. Text PAC to 65075 and the reply will include the exact fee owed. Weigh that against your potential monthly savings to decide whether switching now makes financial sense.
What is the fastest way to switch mobile network in the UK?
Get your PAC code by texting PAC to 65075, then sign up with an eSIM provider. With an eSIM there is no physical SIM card to wait for — you scan a QR code and your new connection is active within minutes. You can start a free 7-day trial with Fuse and be up and running the same day.
Will I lose signal while my number is porting?
Briefly, yes. Most ports complete with a short interruption of less than an hour, typically early in the morning on a working day. Keep your old SIM in a second device if possible, and avoid porting on a day when you are expecting urgent calls. Ports do not process on weekends or UK bank holidays.
The Bottom Line
Switching mobile network and keeping your number in the UK is straightforward once you know the steps — text PAC to 65075, sign up with your new provider, hand over the code, and you are done. With an eSIM the whole thing can happen in minutes, with no plastic card to wait for.
The harder question is making sure you are switching to something genuinely better, not just a different shade of the same problem. If coverage is what has been letting you down, switching to another single-network provider is unlikely to fix it. Multi-network coverage — all four UK networks, automatic signal switching — is a structural upgrade, not just a better deal.
Ready to make the move? Try Fuse free for 7 days and see what your signal could actually feel like.