Company Registration Number (CRN)
What it is
A unique 8-digit number assigned to every UK company by Companies House at incorporation. It never changes, even if the company name changes, and appears on all official documents and the public register.
Why it matters
You use the CRN constantly — to file at Companies House, search your own company record, open UK business accounts and in every formal contract. Keep it to hand.
Common mistake
Giving the UTR (HMRC's 10-digit tax reference) when asked for the CRN. They are different numbers from different bodies — mixing them up delays applications and filings.
Official source
Companies House — Find company information ↗Disclaimer
General educational guidance only — not legal, tax, accounting, immigration, investment or financial advice. We don't guarantee the information is complete, current or suitable for your situation. Always check official sources (GOV.UK, Companies House, HMRC, the relevant professional body) and speak to a qualified professional before acting. Last reviewed: June 2026.