Companies Registration Office
aka CRO, CRO number
The Irish state authority that registers and maintains records of all companies, business names and limited partnerships. Issues the CRO number used as a primary legal identifier.
Last reviewed April 2026
Definition
The Companies Registration Office (CRO) is the central state register of companies and business names in Ireland, operating under the Companies Act 2014. Every Irish-registered limited company, designated activity company, public limited company, unlimited company, or registered business name (RBN) is identified by a CRO number issued at incorporation or registration. The CRO maintains the public register of directors, secretaries, beneficial owners (via the linked Register of Beneficial Ownership), share capital, charges, annual returns (B1 with financial statements) and any name changes. The CRO API allows third parties to look up a company's current legal name, registered office, status (Normal, Strike-Off Listed, Dissolved), and incorporation date, which is why a vendor or accounting software can verify an Irish counterparty's existence before invoicing. CRO numbers are sometimes confused with the Tax Reference Number (TRN) issued by Revenue, which is a separate identifier. Failure to file annual returns on time leads to involuntary strike-off and significant restoration costs.
Why it matters for software choice
Verifying a counterparty (supplier, customer, employer) by CRO number is the cleanest way to confirm an Irish company actually exists, who its directors are, and whether it is in good standing. Software that integrates the CRO API for vendor/customer onboarding catches credit-risk and identity-fraud issues that pure email-domain checks miss.
Authority sources
- Companies Registration Office (www.cro.ie)
- Companies Act 2014 (www.irishstatutebook.ie)
Related terms
NACE Code
EU statistical classification of economic activities. Each business has a primary 4-digit NACE code that identifies its sector. Used by CRO, CSO, Revenue and grant authorities.
eTenders (Ireland)
Ireland's official public procurement portal. All contracts above EU and national thresholds must be advertised here. Source data for Tenderwatch.ie and any procurement-aware vendor selection.