We advise our customers to follow the below recommendations when it comes to submitting the payment data to finAPI to avoid possible payment rejections at the bank.

  1. API parameter purpose - Some banks are unable to process payments without the field. It would be best to provide the purpose to ensure better success rates with payment initiation. Please don’t exceed 140 characters in the purpose.

  2. Supported character set - Depending on the bank’s technology stack and other requirements, special characters in the input might lead to failed payments. We strongly urge customers to stick to the character set below. This impacts the API parameters purpose, endToEndId, recipient.name

    a b c d e f g h i j k l m n o p q r s t u v w x y z
    A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
    0 1 2 3 4 5 6 7 8 9
    / - ? : ( ) . , ' +

    Some banks support umlauts (ä, Ä, ö, Ö, ü, Ü, ß) while some don't. The simplest solution to ensure high success rates would be to substitute umlauts with ae, AE, oe, OE, ue, UE, ss respectively.