We recommend that you login and skip that month when you get a reminder from us. If you are unable to skip within the time limit, your bank will return our transfer request as "insufficient balance". Your bank is likely to charge you ECS return charges. Scripbox doesn't charge you anything.
If this happens twice, one after another, we will automatically cancel your instruction to avoid bank charges piling up for you. You can come back and set it up again when you have money in the bank account.