Company Registration Number Check: Same Legal Entity on Every Supplier Document

This article is provided for information only and is not legal advice. References are accurate as of 24 October 2026. Check current rules with a qualified professional before applying them to a specific supplier file.

A company registration number check confirms that the number written on a supplier document belongs to a real legal entity, and that the name, address and status on the document match what the official register holds for that number. The check only becomes useful when it is repeated on every document in the file: the registration extract, the invoice, the bank letter, the insurance certificate and the signed contract must all name the same entity. This guide lists which field is compared with which field, what a mismatch looks like and what the reviewer does next.

Which identifier belongs to which entity?

Each identifier answers a different question, and mixing them up is the most common source of false alarms and missed errors. Before comparing anything, write down for each document which kind of number it shows.

For France, INSEE explains that the SIRET combines the SIREN of the legal unit with a five-digit NIC for the establishment (INSEE). In Germany a register number is only unambiguous together with the register court and the register type, HRA or HRB (e-Justice portal). In the UK the company number is the key held by Companies House, which publishes the registered address, officers and previous company names for free (GOV.UK).

What does the cross-check matrix look like?

A supplier file needs at least six cross-checks, and each one has a defined failure pattern. The table below is the core of the process: it says what is compared, what a mismatch looks like and what happens next.

Rule of thumb: normalise before you compare. Strip legal-form suffixes ("Ltd", "Limited", "GmbH") only for a first-pass match, then compare the full name including the form. "Ltd" versus "Limited" is a formatting difference. "Ltd" versus "LLP" is a different entity.

How do you check a company registration number in each market?

Use the official register for the supplier's country as the reference, and record what the lookup does and does not prove. A register lookup shows that an entity with that number exists and what its public record says. It does not prove that the PDF in front of you is genuine.

United Kingdom

Search the Companies House register by name or company number and compare the name, status, registered office and officers with the document (GOV.UK). A UK VAT number is separate from the company number and must be checked on its own. Sole traders and partnerships have no company number, so the file needs a different identifier.

France

The legal entity carries a SIREN; each establishment carries its own SIRET; the intra-EU VAT number is a separate identifier (INSEE). For a French supplier, check that the SIRET on the invoice starts with the SIREN on the extract, then look the SIREN up in the public company directory. If the SIREN matches but the establishment is closed, the supplier is real and the document is wrong.

Germany

Always capture three elements together: register court, register type (HRA or HRB) and number. The Handelsregister portal at handelsregister.de is the official entry point for the register data. The USt-IdNr is a different identifier; the German tax office (BZSt) runs a confirmation procedure for foreign VAT numbers (BZSt).

Spain and Portugal

In Spain the NIF identifies the company. A nota simple from the Registro Mercantil reproduces the register entries, but it is informational; a formal certification is needed to rely on the data against third parties (Consumoteca). In Portugal the NIPC identifies the entity, and the certidão permanente is viewed online with an access code. Compare the NIPC and the company name on that certificate with the contract and invoice.

EU VAT: VIES

VIES confirms whether a VAT number is valid, but whether it also returns the name and address depends on the member state, because national authorities decide what they disclose (European Commission). Save the result with a date: a VAT check is a dated observation.

Which mismatches are harmless and which are red flags?

Harmless mismatches are about presentation; red flags are about identity. The table separates them.

A new bank account on an existing supplier combined with a changed address is the pattern most often linked to payment redirection. Treat it as an identity question, not a typing error.

What do users actually ask about this check?

Users on specialised forums often ask two things. The first: "Can I just trust the number in the Impressum or invoice footer?" No. That number is the supplier's own statement; compare it with the register. The second: "The name on the invoice is not the name on the register, is that a problem?" It depends on whether the number matches. If the number is right and the name is a trading name, record it as an alias. If the number belongs to another company, stop the onboarding.

How do you run the check step by step?

1. Extract the identifier, legal name and address from each document, keeping the document type next to each value.
2. Query the official register for the number and save the result with the date.
3. Compare each extracted value with the register entry, using the matrix above.
4. Classify each difference as formatting, alias or identity.
5. For identity differences, contact the supplier through a channel taken from the register or an earlier contract, never from the suspect document.
6. Record the decision and the evidence in the supplier file.

For a deeper view of the document list, see our supplier onboarding documents checklist and the article on cross-document verification. The overall method sits in the document verification guide.

How can the check be automated?

CheckFile compares the fields extracted from each document, such as legal name, registration number, address and account holder, with each other and with the register data you supply, and lists the differences for a reviewer. It does not decide that a document is authentic; it shows where the file is inconsistent so a person can act. See how document validation works and the pricing.

FAQ

What is a company registration number check?

It is a comparison of the registration number and name on a document with the official register entry for that number. It confirms that the entity exists and that the document matches its public record.

Is the VAT number the same as the company registration number?

No. The VAT number is a separate identifier. In France the SIREN, the SIRET and the VAT number are three different things, and in Germany the USt-IdNr is separate from the register court, type and number.

Does a register lookup prove the document is genuine?

No. It proves that an entity with that number exists and shows its public data. A forged extract can still carry a real number, which is why the name, address, status and bank holder must also match.

How often should the check be repeated?

At onboarding, whenever the supplier changes bank details or address, and at each periodic review. A status check from last year says nothing about today.