How do you find and check a company registration number?

A company registration number is an identifier assigned by a particular company register. Start with the country or state of incorporation and the exact legal name: the same trading name may belong to several legal entities, and a number without its issuing register is easy to misread.

Where can you find the number?

Search the official register named on the company's incorporation document or contract. The UK Companies House service (opens in a new tab) shows a company number alongside a matching legal name. For a US entity, use the relevant state or territorial registry: there is no single national company-registration number. For example, New Mexico's Business Search accepts a name or Business ID.

Compare the register result with the legal name, jurisdiction, entity type and address in the agreement. Keep the registry URL, identifier, retrieval date and any document issue date. If several results have similar names, request the incorporation document or another identifier before choosing one.

A company description and headquarters country can help explain the business, but neither necessarily identifies the place of incorporation. A group may have a head office in one country and a contracting subsidiary registered in another. Check the incorporation jurisdiction and registered office against the record for the legal company actually signing the agreement.

Is a tax number the same thing?

Usually these identifiers answer different questions. A US EIN is a federal tax identifier; a state's business ID is issued by its business registry. In Denmark, the CVR number identifies the business, while a P-number identifies a production unit. In Hong Kong, the Business Registration Number also serves as the Companies Registry's Unique Business Identifier under its UBI arrangements. Label each number with its issuer and purpose instead of treating every number on a document as interchangeable.

Which incorporation document should you use?

A certificate of incorporation or formation records that an entity was formed under an issuing authority. Articles, a constitution or an LLC agreement describe rules and powers, while a current register extract or later filing can show more recent recorded particulars. Ask for the document that answers the review question and compare its number, entity name, jurisdiction and date with the register. A formation certificate alone does not establish today's owners or signing powers.

A practical matching example

Suppose a supplier's invoice uses a brand, the contract names a limited company and an onboarding form supplies a tax number. Search the legal company in its incorporation register, copy the number from the matching result and compare the contract's name and address. Keep the tax number in a separate field. If the invoice belongs to a different group entity, request evidence connecting that entity to the contract before relying on the registry result.

What does the number establish?

A number helps locate the right record; it does not by itself confirm current status, signing authority or beneficial ownership. Check a dated extract or relevant filing for the specific question, then request company-held records if the register does not identify the current owners or authorised signer. The overseas-company verification guide shows how to connect these records. Fill Easy's country document catalogue lists available extracts and their fields; CorpVerify can help obtain supported records.