Small, free utilities for people working with European company identifiers. No signup, no key, no metering. They are free because they cost nothing to run: one is pure arithmetic in your browser, the other queries a public open-data register directly.
Check the check digit on a Spanish NIF or CIF, a French SIREN or SIRET, a Polish NIP or REGON, a Norwegian organisation number, a UK company number, an Irish CRO number, or any EU VAT number. It distinguishes between identifiers that carry a real check digit (Spain, France, Poland, Norway) and those that do not (the UK and Ireland), because "well-formed" and "exists" are different claims. Open the validator.
Search the GLEIF register by Legal Entity Identifier or company name. Returns legal name, jurisdiction, legal form, registration status and renewal date, with ISO 7064 checksum validation before the lookup. Open the LEI lookup.
Neither tells you whether a company exists, who its directors are, what it does, or whether it is in insolvency proceedings. Those need registry data. The Prometiam API covers Spain, France, the UK, Ireland, Poland and Norway from one key, with 1,000 free calls a month and no credit card.