# XV-FI-14

Source: https://xmlvalid.com/rules/XV-FI-14

> The Finnish VAT number '…' is not FI followed by the eight digits of a valid business ID.

- Level: warning
- Rule sets: Finvoice 3.0 calculation and payment rules Implementation guidelines 2.6 (16 September 2025)
- Context: `/Finvoice/SellerPartyDetails | /Finvoice/BuyerPartyDetails`
- Test: `not(starts-with($vat, 'FI')) or (matches($vat, '^FI[0-9]{8}$') and fi:ytunnus(concat(substring($vat, 3, 7), '-', substring($vat, 10, 1))))`

Validate a document against these rules: https://xmlvalid.com/validate