Incorrect VAT validation for Poland when total sum modulo with 11 is 10

se-panfilov / jsvat

Check the validity of the format of an EU VAT number

http://se-panfilov.github.io/jsvat

MIT License

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Incorrect VAT validation for Poland when total sum modulo with 11 is 10 #131

Open banafsheh-unify opened 1 year ago

banafsheh-unify commented 1 year ago

It seems there is an issue with VAT validation for Poland. According to this wikipedia page (https://pl.wikipedia.org/wiki/Numer_identyfikacji_podatkowej) and the spec here (https://romek.info/ut/nip-rego.html#nip) the following numbers are invalid VAT numbers:

0000000000
1234567890 The above links are in Polish, I used google translate to make sense out of the parts where it states that the modulo of the calculated sum cannot be equal to 10, otherwise that VAT is invalid.

TShockman commented 1 year ago

At least one issue occurs when checksum mod 11 is 10, according to the spec this should indicate an invalid VAT number. An english version of the specs can be found here https://ec.europa.eu/taxation_customs/tin/#/check-tin (download file under "Get the TIN specifications", page 42).

This is the case with VAT number 1234567890.