Yes, this is easily possible via the customer menu.
To do this, click on your name at the top right and then on "Credit account".
There you can top up a minimum of 5.00 euros and a maximum of 500.00 euros. The credit will be used and charged primarily for future invoices.
Please note, however, that for money laundering law reasons we cannot pay out any credit if you are still an active customer with us.
As long as you still have an active contract with us, we are therefore unfortunately unable to transfer any credit already deposited back to you.