What are the costs for rejected direct debits?

The cost for a rejected direct debit is €10 per rejected payment.

This happens where there are insufficient funds in your account to cover a direct debit payment.
For example, if your Internet service provider charges €30 on the 3rd day of each month for your subscription, but you only have €20 in your account at that time, the direct debit will fail. 

If, at the time of the direct debit, your balance is less than the amount due, Nickel will debit part of the fees of the available balance in your account. The remaining amount will be debited once there are sufficient finds in your account.

For example: if you owe €10 in rejection fees but you only have €7 in your account, Nickel will debit €7 first. You will still owe Nickel €3, which will be debited later once there are sufficient funds in your account.