What happens if there is not enough money in my deposit account to pay all the fees I intend to pay by debit order?

The EPO processes debit orders immediately, provided there are sufficient funds in the deposit account. If you are paying fees for a single application by debit order, these fees are booked in ascending order of their fee codes, with the exception of the appeal fee (011) and the opposition fee (010), which are booked first.

If you are paying fees for multiple applications by debit order, the fees for the application with the lower application number are booked first (ascending order of application number ("PCT" before "EP")) (point 7.3 ADA).

The EPO books fees in this order as long as the funds allow. If the account does not contain sufficient funds to cover all the fees you intend to pay for an application (shortfall), no other debit order is booked until the account is adequately replenished (point 7.4.1 ADA).