Reference number based on the Finnish standard
The Finnish reference number is used in domestic payments. In order to avoid typing errors, the reference number should be short, but no shorter than four (4) digits (three digits and a check digit). The maximum length of a reference number is 19 + 1 digits. The reference number is printed in the field reserved for it in groups of five digits separated by an empty character space. The leading zeros are not printed. The reference number must also be included in the part comprising the invoice, if any. Guidelines to the structure of the creditor reference are annexed to this document.
12 34561
00000000000001234561
Calculation of check digit
The calculation of check digit is done using 7-3-1 method:
- The digits in the basic reference data to be verified are multiplied by the weights 7, 3, 1... right to left .
- The multiplied sums are added up
- The sum is subtracted from then nearest figure ending in zero.
- The resulting difference is the check digit, which is entered as the last digit in the reference number.
Source and more information of 7-3-1 method in Estonian Banking Assosiation.
Finnish reference in XMLdation service
Finnish reference check is active for all Finnish pipes, and is executed unless RF Creditor Reference is used.
Despite FKL stating that length of finnish reference should be 4-20 characters, validator accepts 3-20 characters, as "123" is considered to be valid reference according to certain Finnish banks.
Validator accepts both paper and machine readable formats of Finnish Reference.
Sources:
FKL, Kotimaisen viitteen rakenneohje: http://www.fkl.fi/teemasivut/sepa/tekninen_dokumentaatio/Dokumentit/kotimaisen_viitteen_rakenneohje.pdf
FKL, Bank Transfer Guidelines: http://www.fkl.fi/en/material/publications/Publications/Bank_Transfer_Guidelines_2011.pdf
EBA, The standard of reference number: http://www.pangaliit.ee/en/settlements-and-standards/reference-number-of-the-invoice