Change repayment terms of some loans

Changing the payment method and / or date is only possible on loans that are TO_REPAY or TO_REPAY_FEES.

Postponing loan repayment date is only possible once.

If loan is supposed to be repaid using a sepa direct-debit, you may not be able to change the debited account number less than 3 days before the scheduled payment date because payment has already been instructed. In such case you'll get a 400 error telling you that the payment cannot be cancelled anymore.