@Sanduni Ariyarathna I will give you a generic answer since I was the design owner of this area under my previous IFS role. ISO20022 is a generic payment format and we didn’t had any idea to introduce the country specific validations to this format. Basically, you can use two types of bank account in ISO20022 payment address, i.e, domestic account number and International Bank Account Number (IBAN). If you are going to use an IBAN number starting with two alpha numeric chracters and if third digit is a number, the system will do the IBAN validation. For an example, if you type “PL12”, there will be a validation to check whether you are going to enter a correct IBAN number based on IBAN Validation logic. But, there won’t be any validation for the domestic account number. If I remember correctly, even during PL localization, there was no intention to modify the generic format.

@Eranda  Many thanks for the detail explanation.