In the 1NCE Customer Portal we offer a so-called "Auto-Top-Up" feature, which you can use to automatically top-up your cards. Just deposit a valid credit card in the customer portal to activate this feature. The volume of your SIM cards is automatically checked by the system every day at 06:00 and 18:00 CET. As soon as more than 80% of the volume is used, a top-up is automatically triggered. You can find more information at https://help.1nce.com/dev-hub/docs/portal-sims-sms#auto-top-up .