Auto-refill tops up your credit balance when it runs low, so your requests never stop for lack of credit. It applies to the whole organization.
Set up auto-refill
Check that the organization has an auto-refill card on Settings > Billing > Payment details. It is the owner's card; any billing manager can change it.
Open Settings > Billing. In Balance and auto-refill, click Set up auto-refill (or Edit auto-refill).
Choose the balance that triggers a refill (When the balance falls below) and the amount each refill charges.
Optional: set a Monthly limit. It counts every purchase in the month, manual top-ups included. Leave it empty for no limit.
Save.
If a refill fails
A failed refill pauses auto-refill until a card is added or replaced. A declined card or a reached limit is emailed to the owner, billing managers and billing contacts.
More details in the documentation: Buying Credits & Auto-Refill.