Company Shark

UK company number explained

A UK company number — the Company Registration Number or CRN — is the unique 8-character identifier Companies House gives a company when it incorporates. It never changes for the life of the company. England & Wales numbers are 8 digits (e.g. 01234567); Scottish companies are prefixed SC, Northern Irish ones NI, and other forms have their own letters (OC for LLPs, etc.).

What the prefixes mean

A purely numeric 8-digit number (often shown with a leading zero, like 00012345) is an England & Wales company. Common letter prefixes include SC (Scotland), NI (Northern Ireland), OC (limited liability partnership in England & Wales), SO (LLP in Scotland), and FC (overseas company). The prefix tells you the jurisdiction and broad type.

The CRN is not the same as a VAT number or a tax reference. It is the canonical key for the company on the register — the most reliable way to identify a business, because names can change or be shared.

Frequently asked

Where do I find a company’s registration number?

It is on the public register — shown on every Company Shark company page — and companies must also display it on letterheads, invoices, emails and their website.

Why do some numbers have leading zeros?

England & Wales numbers are always 8 characters, so shorter numbers are zero-padded (e.g. 12345 is stored as 00012345).

Does the company number change if the company is renamed?

No. A company can change its name freely, but the registration number stays the same for its entire existence — which is why it is the best identifier to use.

Is the CRN the same as a VAT number?

No. The CRN is issued by Companies House; a VAT number is issued separately by HMRC only if the business registers for VAT.

Related guides

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