Need to swap your SIM?
If your SIM is lost or damaged, or it doesn’t fit your new device, we can send you a replacement and transfer your number to your new SIM.
To request a replacement SIM, you’ll need to contact us or visit an O2 store. If you're an O2 Business customer, please sign in to My O2 Business to swap your SIM.
If you're making the request from a computer or tablet, make sure you have your phone with you, as we’ll send a security text before we do the swap.
If you’re popping into one of our stores to swap your SIM, remember to bring your passport or driving licence with you, as ID.
Before swapping, you’ll need to check that your SIM is the correct type. Our Pay Monthly SIMs are set up differently to Pay As You Go ones and they’re not interchangeable, so you’ll only be able to swap on to a SIM that matches your account type.
Help with your SIM
Need help with your SIM? We’ve got you covered. You’ll find all the information you need in the sections below.
Plastic SIMs
Plastic SIMs come in three different sizes - standard, micro and nano. The SIM pack has perforated edges, so you can just pop out the SIM that’s the right size for your device.
If you're not sure which size SIM you need, have a look at the instructions that came with your device.
Don't try to cut your old SIM down to size, as it could break or get stuck in your device. If you need to use your nano or micro SIM as a standard SIM in an older device, you can get a free adaptor from one of our stores.
eSIMs
Some devices allow you to use an eSIM. Check out our eSIM help page to find out more.
To request a new SIM, contact us or visit an O2 store.
New Pay Monthly customers
If you’re using a plastic SIM, it’ll be ready to use straight away. Just pop it in your device and you're good to go.
If you’re using an eSIM, you’ll just need to download the eSIM profile to your device, using the QR code in your eSIM pack.
New Pay As You Go customers
If you have a Pay As You Go plastic SIM, you’ll need to put it in your device and then top up to activate it.
Existing Pay Monthly customers
If you have a new plastic SIM, you can move your number across to your new SIM by signing in to My O2 and choosing “Install your SIM”. If you're an O2 Business customer, please sign in to My O2 Business to swap your SIM.
If you use an eSIM, download the new eSIM profile to your device.
If you have your current SIM and it’s still working, don’t remove it from your device straight away – we’ll need it to send you a security text.
If you don’t have your current SIM, or it’s no longer working, insert your new SIM into your device. If your device connects to the network, you can start using it straight away. If your device doesn’t connect to our network, give us a call for more help. You’ll need to confirm your identity, so we can protect against fraud.
You’ll also need the 13-digit SIM Serial Number (SSN) for your new SIM, which begins 00. You’ll find this printed on the back of your plastic SIM.
SIM swaps can take up to 24 hours to complete. Once you lose signal with your original SIM, turn your device off. If you’re using a plastic SIM, pop it in your device. Then switch your device back on and wait for it to connect to the network.
If you've blocked your SIM from entering your PIN too many times, you'll need to request your PUK (Personal Unblocking Key) code. Fill out the form to unblock your phone.
If your SIM has been lost or stolen, you'll need to contact us by phone to block your SIM and order a replacement.
Your replacement SIM will come activated and set up with your existing number, so all you need to do is insert it into your device.
Last updated: 10/02/2025
