With the latest release we are introducing up to three custom SIM fields for each customer.

Custom fields can be created in the Edit Columns pop-up by Admin users.

The fields can be named as you like with a maximum of 25 characters. They will appear as columns in the SIM list (if configured to be visible). 

You can enter values for custom fields in the SIM details view. Just double click or use the pencil icon next to the field to start editing.