Log in to the Spacetalk app and tap Membership at the bottom.

You'll see a list of your active plans. Select the plan you want to replace the SIM for.

From the available options for that plan, choose Replace SIM.

You'll see a list of the steps involved. If you're using a physical SIM, have it ready. When you're ready, tap Continue.

Choose between physical SIM and eSIM.

eSIM: make sure your device is eSIM compatible before proceeding. Tick the box to acknowledge, then tap Continue.

Physical SIM: enter the SIM number shown on the SIM (it typically begins with 4000), then tap Continue.

To prevent unauthorised SIM replacements, you'll need to enter an access code. Choose to receive it by SMS or email (to the details on your Spacetalk Mobile service), then tap Send Code.

Once you've received the code, enter it where prompted and tap Verify.

Your old SIM will be disconnected, and your new SIM will become active with the same plan and number. You can start using your service straight away, though we recommend turning the device with the SIM off and on again so it reads the new SIM.