Guide · Ireland · CRO
What is a CRO number?
A CRO number is the company registration number the Companies Registration Office (CRO) gives every company incorporated in Ireland: a plain number of usually 5 to 7 digits, not a tax number. The CRO is the State's statutory register for every company and business name: here is what it holds, how its numbers work, and how to query it programmatically.
Key facts: Ireland
Register: Companies Registration Office (CRO)
Identifiers CRO number
- Company recordsYes
- OfficersNo
- Insolvency noticesNo
- Corporate eventsRegister changes
- MonitoringYes
- Financial statementsNo
- VAT numberNo
- NACE classYes
- UpdatedDaily
Price From EUR 9.99 a month (Starter plan)
The short version
Have a CRO number or a name to check? Use the free CRO number lookup: it is a CRO company search that returns the company’s name, type and status.
The Companies Registration Office (CRO) is Ireland's statutory registrar. Every company incorporated in Ireland is registered there and receives a CRO number, and every company must file an annual return. The register is public: company name, registered address, status, incorporation date, company type and directors are all disclosable.
For counterparty verification the CRO is the authoritative source — a company either appears on it or does not legally exist in Ireland.
CRO numbers
A CRO number is a plain sequential integer, typically 5 to 7 digits, with no check digit and no letter prefix. That matters when you validate input: unlike a Spanish NIF or a UK company number, there is no checksum to verify a CRO number offline. The only way to know it is real is to look it up.
Two consequences for an integration. First, do not write a regex that rejects short numbers — older companies have low numbers. Second, store it as a string, not an integer, if you ever intend to zero-pad for display.
Irish company types
| Form | What it is |
|---|---|
| LTD | Private company limited by shares — the default form since the Companies Act 2014. Single-document constitution, may have a single director. |
| DAC | Designated Activity Company — limited by shares but with a stated objects clause. Common where a lender or regulator requires a restricted purpose. |
| PLC | Public limited company — may offer shares to the public. |
| CLG | Company limited by guarantee — no share capital. The usual form for charities, clubs and management companies. |
| UC / ULC | Unlimited company — members have unlimited liability. Historically used to avoid publishing accounts, though that exemption has narrowed. |
Business names (sole traders and partnerships trading under a name) are registered separately and are not companies — a registered business name has no separate legal personality, which is a common source of confusion in onboarding.
What the CRO publishes
Company name and any former names, registered office address, company type, status (normal, strike-off listed, dissolved), date of incorporation, and the annual-return filing history. Directors and secretaries are on the register, and Ireland also maintains a separate Register of Beneficial Ownership (RBO).
Access to the RBO was restricted following the November 2022 CJEU ruling that struck down general public access to EU beneficial-ownership registers; it is now available to designated persons and competent authorities under a legitimate-interest test rather than to anyone. That is why very few APIs can honestly claim Irish UBO coverage.
Querying Irish companies from an API
Prometiam serves Irish companies from the CRO at company level — name, CRO number, address, status, type and incorporation date — alongside every other registry the API covers, under one schema and one API key. Irish directors are not yet served; we would rather say that than imply coverage we do not have. The Ireland company data API guide covers the CRO number lookup and monitoring, and Irish companies that have stopped filing carry a strike-off warning signal.
curl -H "Authorization: Bearer rk_live_..." \ "https://api.prometiam.com/functions/v1/risk-api/companies/search?name=ryanair&country=IE"
The free trial covers 500 credits over 14 days with a card required and nothing charged for 14 days, which is enough to evaluate Irish coverage against your own book.
FAQ
How do I do a CRO company search?
Search by CRO number or company name in the free CRO number lookup on this site: it returns the Irish company’s name, type and status from the Companies Registration Office register, with no sign-up. For bulk checks or automation, the same record is one API call away.
What is a CRO number?
A CRO number is the registration number the Companies Registration Office gives a company when it is incorporated in Ireland. It is a plain sequential integer, usually 5 to 7 digits, that identifies the company on the Irish register and is what you look the company up by. It is not the tax reference number.
What is the CRO in Ireland?
The CRO is the Companies Registration Office, 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.
Is a CRO number the same as a tax number?
No. The CRO number identifies the company on the companies register; the Revenue tax reference number is separate and is not published by the CRO.
Can I validate a CRO number offline?
No — there is no check digit. You have to look it up.
Does the CRO publish beneficial owners?
Not publicly. Irish UBO data sits in the separate RBO, and general public access was removed after the 2022 CJEU ruling.
Does Prometiam cover Irish directors?
Not yet — Irish coverage is company-level. UK directors and PSC owners are served, as are Spanish, French and Norwegian officers.
What does CRO stand for in Ireland?
CRO stands for Companies Registration Office, Ireland's statutory registrar of companies and business names. In a company context, a CRO number is the registration number that office gives the company.
What does a CRO number mean for an Irish company?
It is the company's registration number on the Irish register, also called the company number. Quote it on contracts, onboarding forms and KYB checks to identify exactly which company you mean, because company names can be similar and the number points to one entity.
How many digits does a CRO number have, and what does it look like?
Usually 5 to 7 digits, written as a plain number with no letter prefix and no check digit. Older companies have shorter numbers, so do not reject short ones. Store it as a string if you ever pad it for display.
Is a CRO number the same as a company number or a company registration number?
Yes. In Ireland the CRO number, the company number and the company registration number are the same thing: the number the Companies Registration Office assigns at incorporation. It is not the Revenue tax reference number and not a VAT number.
Are CRO numbers public, and does every Irish company have one?
Yes to both. Every company incorporated in Ireland is registered and receives a CRO number, and the register is public: name, registered address, status, incorporation date, company type and directors are disclosable. A registered business name is separate and is not a company.
Can two different companies have the same CRO number?
No. A CRO number identifies one company on the register. If two names appear to share a number, one of them is probably a registered business name or a typing error, so look the number up and compare the legal name.
What is the CRO number for a company in Northern Ireland?
Northern Ireland is not covered by the Irish CRO. Companies there are registered at Companies House in the UK and carry company numbers with the NI prefix. See the guide on what Companies House is for how those numbers work.