How to Do a SIM Swap on Any UK Network
What Is a SIM Swap?
A SIM swap is the process of transferring your phone number and account from one SIM card to another. Your old SIM is deactivated and a new SIM is activated in its place. You keep the same phone number, the same plan and the same account — only the physical card changes.
This is sometimes called a SIM replacement or SIM change. It is different from porting your number to a new network, which requires a PAC code.
When Do You Need a SIM Swap?
- New phone with a different SIM size — for example, moving from an older phone that uses a micro SIM to a newer phone that requires a nano SIM.
- Damaged SIM card — if your SIM is cracked, scratched or no longer reading properly.
- Lost or stolen SIM — you need a replacement card to restore service on your number. See our guide on what to do if your SIM is lost or stolen.
- SIM card not working after a software update — rare, but occasionally a SIM needs replacing after a phone update causes connectivity issues.
How to SIM Swap by Network
| Network | How to Request | Cost |
|---|---|---|
| EE | Call 150 from your EE phone, or visit an EE store | Free |
| Vodafone | My Vodafone app, or call 191 | Free |
| O2 | My O2 app, online at o2.co.uk, or visit an O2 store | Free |
| Three | Call 333 from your Three phone, or visit a Three store | Free |
All major UK networks provide SIM swaps free of charge. If you are ordering by phone or online, the new SIM is typically posted to your registered address and arrives within 1–3 working days. In-store swaps can be done on the spot.
What Happens During a SIM Swap
- You request a replacement SIM from your network using one of the methods above.
- Your network sends you a new SIM card (or you collect one in-store).
- You insert the new SIM into your phone.
- The old SIM is deactivated and the new SIM activates — this usually happens within a few hours but can take up to 24 hours.
- During the switchover, you may temporarily lose mobile service. WiFi will still work.
- Once active, your phone number, plan and allowances carry over to the new SIM.
After Your SIM Swap
Once your new SIM is active, check the following:
- APN settings — your phone should configure these automatically, but if you cannot access mobile data, you may need to update them manually. See our APN settings guide for instructions by network.
- Voicemail — you may need to set up your voicemail again. Dial your network's voicemail number to check.
- WiFi calling — if you had WiFi calling enabled, re-enable it in your phone settings after the swap.
- Two-factor authentication — any services using SMS-based 2FA will work as normal once the new SIM is active, since your number has not changed.
Managing SIM cards across a business fleet? Connection Technologies handles provisioning, eSIM setup and SIM swaps for your entire team. Get a free quote or call 0333 015 2615.
