A credit agreement defines the dates by which the borrower must pay his monthly instalments. If an instalment payment is not received by the lender on time or not in the agreed amount, the lender can send the borrower a "reminder".
The costs for the reminder are charged to the borrower and added to the remaining loan amount.
To avoid a reminder and the associated costs, monthly payments should always be transferred a few days before the due date. The easiest way to do this is to set up a standing order that automatically transfers the amount each month.