Verify a supplier before payment: Belgium & Poland (incl. the White List account check)

Registry identity, VAT number checked against VIES, Peppol reachability (BE), White List status and account check (PL), IBAN form check + bank identification, mandate calendar, and a deterministic pret_a_facturer verdict whose reasons are a closed list, each classified blocking or informational and traced to its source. With an iban supplied, verdict.non_verifie sits NEXT TO the verdict and names what is never checked (account existence, holder name): the Polish White List proves the account is DECLARED by that taxpayer, not who holds it. An unavailable source yields non vérifiable, never a false invalid. Also carries provenance[] (official register, licence and as_of date per block); the Polish account check returns the exact date sent to the White List, the date the buyer can rely on.