The Companies Registration Office is Ireland's statutory register of companies and business names. Every Irish company is registered there, receives a CRO number, and must file an annual return. Company name, address, status, type, incorporation date and directors are public.

What format is an Irish CRO number?

A plain sequential integer, usually 5 to 7 digits, with no check digit and no letter prefix. Because there is no checksum you cannot validate a CRO number offline - it has to be looked up.

Does the CRO publish beneficial ownership?

Not publicly. Irish beneficial ownership is held in the separate Register of Beneficial Ownership (RBO), and general public access was removed after the November 2022 CJEU ruling. Access now runs through a legitimate-interest test.

Can I query Irish companies from an API?

Yes. Prometiam serves Irish companies from the CRO at company level - name, CRO number, address, status, type and incorporation date - alongside Spain, France, the UK, Poland and Norway under one key. Irish directors are not yet served.

What is the CRO? Ireland's Companies Registration Office

The Companies Registration Office is Ireland's statutory registrar. Every company incorporated in Ireland is registered there, receives a CRO number, and must file an annual return. The register is public: company name, registered address, status, incorporation date, company type and directors are all disclosable.

CRO numbers

A CRO number is a plain sequential integer, typically 5 to 7 digits, with no check digit and no letter prefix. Unlike a Spanish NIF or a UK company number there is no checksum, so a CRO number cannot be validated offline — it has to be looked up.

Irish company types

LTD (private company limited by shares, the default since the Companies Act 2014), DAC (designated activity company, with a stated objects clause), PLC (public limited company), CLG (limited by guarantee, used by charities and management companies) and UC/ULC (unlimited). Business names for sole traders and partnerships are registered separately and are not companies.

Beneficial ownership

Irish UBO data lives in the separate Register of Beneficial Ownership, not the CRO. General public access was removed after the November 2022 CJEU ruling and now runs through a legitimate-interest test, which is why very few APIs can honestly claim Irish UBO coverage.

Querying Irish companies

Prometiam serves Irish companies from the CRO at company level alongside Spain, France, the UK, Poland and Norway under one schema and one API key. Irish directors are not yet served. Free tier: 1,000 calls a month, no credit card.

Read the full guide · Get a free API key

Official source: the CRO

Frequently asked questions

What is the CRO?: The Companies Registration Office is Ireland's statutory register of companies and business names. Every Irish company is registered there, receives a CRO number, and must file an annual return. Company name, address, status, type, incorporation date and directors are public.
What format is an Irish CRO number?: A plain sequential integer, usually 5 to 7 digits, with no check digit and no letter prefix. Because there is no checksum you cannot validate a CRO number offline - it has to be looked up.
Does the CRO publish beneficial ownership?: Not publicly. Irish beneficial ownership is held in the separate Register of Beneficial Ownership (RBO), and general public access was removed after the November 2022 CJEU ruling. Access now runs through a legitimate-interest test.
Can I query Irish companies from an API?: Yes. Prometiam serves Irish companies from the CRO at company level - name, CRO number, address, status, type and incorporation date - alongside Spain, France, the UK, Poland and Norway under one key. Irish directors are not yet served.