SIM support

Learn how to activate your SIM, order a new SIM, and more.

Activate your replacement SIM

Recently joined us?

There’s no need to activate your new SIM. Put it into your phone, and it’ll connect to our network automatically. 

Got a replacement Pay Monthly SIM?  

Your replacement SIM should be active already. Put it into your phone, and it’ll connect to our network straight away. You’ll know it’s active if you can see signal bars. You may need to turn Wi-Fi off in your phone settings to see the signal bars. 

SIM not working? Log into or register your account online or on the Three app. 

Got a replacement Pay As You Go SIM?  

Like our Pay Monthly SIMs, you can activate your Pay As You Go SIM by putting it into your phone. It’ll connect to our network automatically, and you’ll know it’s ready to use when you can see signal bars. 

Still need some help?  Head to our Pay As You Go support page. 

More SIM support

Lost or stolen SIM

If you’ve lost your phone or had it stolen, get in touch. We’re here to help.

Finding your SIM number

Here’s our easy guide on how to find your SIM number.

Using Dual SIM devices

Here are some useful tips on how to use a device with 2 SIMs.

Get a replacement SIM

Log into your account online to order one now. 

Using SIM adapters

Learn more about how to use SIM adapters.

Normal, micro, or nano?

Learn the difference between the various SIM sizes.

eSIM support

Find out more about using an eSIM in your device.

Just upgraded?