Page last modified 12:56, 21 May 2018 by villes

Finanssiala - AOS2

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    Version as of 20:48, 17 May 2022

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    Rules and definition

    AOS2 (additional optional service) is an optional extension to EPC's rules regarding the usage of Remittance Information, increasing the maximum number of Strd elements from 1 to 999 and the allowed size of the element from 140 to 280. However, only Finnish banks are able to accept AOS2 structured messages.

    Without AOS2, due to Strd's size restriction, transaction block has room to transfer only reference number. With AOS2, it's possible to send multiple invoices and credit notes along with the reference number.

    FA has a set of rules regarding correct usage of AOS2. The rules are shown in this graphic table:

    The structure and element names are for pain.001.001.03, however the usages of rules apply to pain.001.001.02 as well.

    *Rule 1: The value of InstdAmt must be equal to the combined value of the sum amount of all invoices minus the sum amount of all credit notes. 

    *Rule 2: The combined value of the sum amount of all invoices minus the sum amount of all credit notes must be positive.

    The table includes four different cases. They are listed and explained below:

    Case 1: Normal invoice with invoice number

    Case 2: Normal invoice with ISO 11649 creditor's reference

    Case 3: Credit note with invoice number

    Case 4: Credit note with ISO 11649 creditor's reference


    The "Values"-column refers to the valid values of the elements. The "Max"-column refers to the maximum occurences of the element.

    The value "CINV" refers to a invoice and "CREN" to a credit note.


    If AOS2 content is sent to banks not supporting AOS2, usually only the Ustrd field is transmitted forward. 

    The interpretation of these rules may vary from bank to bank.