Business SIM & eSIM support 

There are two options: 

1. Order a replacement SIM - you can do this by logging into your online account. 
2. Use a SIM adapter - this lets you use a smaller SIM in a device that needs a larger SIM.
   • Using our Device support page, determine the size SIM you need for your device.
   • If you’ve been given two SIM adapters inside a large rectangle, push the correct SIM adapter out of the plastic rectangle.
   • Place the adapter on a flat surface with the slot facing up. 
   • Insert the new SIM, gold side up, into the adapter until it is flush.
   • Insert the adapter into your device's SIM slot.

Some devices support Dual SIM, allowing you to use two SIMs in your phone. However, there are some key points to note:

• Older models might only support one Three SIM. In such cases, set the Three SIM as primary. Setting it as the secondary SIM would require 2G, which Three doesn't support. 
• Use a SIM from another network as the secondary one, as a Three SIM will produce a ‘No service’ message.
• If your device supports eSIM, you can use Dual SIM with just one physical slot. 
• Some devices also allow the second slot to be used for a memory card. 

For more information about eSIM and Dual SIM capabilities, visit our Device support pages.

If you request a replacement SIM through your online account, this is free and you will receive an eSIM. For replacement physical SIMs you will be charged £4.26 for each SIM required.