The CRO in Ireland Explained: What It Does and the Filings Every Company Must Make
What the Companies Registration Office does, plus the CRO forms every Irish company must file (A1, B1, B2, B10, B5) with deadlines, fees and penalties.
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- Abbey Blue Formations
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- 6 min read
Every Irish limited company has a relationship with the CRO Ireland register from the day it is formed. Your company is created by a CRO filing, and it stays on the register only as long as you keep filing.
This guide explains what the Company Registration Office does, how to search the register, and the key forms your company must file after incorporation. It covers deadlines, fees and what happens if you miss them.
What is the CRO in Ireland?
To answer what is CRO: the Companies Registration Office is the State body that incorporates companies and registers business names in Ireland. It sits under the Department of Enterprise, Tourism and Employment.
The CRO also receives the filings companies must make after incorporation, enforces the filing rules in the Companies Act 2014, and makes company information available to the public.
Don't confuse the CRO with other bodies:
- CRO: company registration, officers, registered office, annual returns
- Revenue: tax registration, returns and payments
- RBO: the Register of Beneficial Ownership, which records the people who own or control the company. See our guide to the RBO five-month deadline.
Searching the CRO register and finding a CRO number
The Ireland company register is searchable through CORE, the CRO's online system. You can run a CRO search by company name or registered number.
A search brings up the company's basic public details and the documents it has filed. Copies of filed documents cost €2.50 per document image, and a printout of basic company details costs €3.50.
As for what is a CRO number Ireland founders keep being asked for, it is the unique registration number the CRO gives your company at incorporation. You'll need it for bank accounts, tax registration, contracts and every later CRO filing.
Registering a company: Form A1
A new company is registered by filing Form A1 online, along with the company's constitution. The CRO fee is €50.
Before filing, check that your chosen name is available. Our company name check does this for you. The CRO aims to issue a certificate within ten working days of receiving complete documents under its ordinary online scheme, and within five working days under its fast-track scheme.
Key CRO forms every company files after incorporation
Incorporation is only the start. These are the forms most small companies file:
| Form | What it's for | Deadline | CRO fee (online) |
|---|---|---|---|
| B1 | Annual return | Within 56 days of the annual return date | €20 |
| B10 | Change of director or secretary, or their details | Within 14 days of the change | Free |
| B2 | Change of registered office | Within 14 days of the change | Free |
| B5 | Return of allotments (new shares issued) | Within one month of allotment | €15 |
| B7 | Change in share capital | Within one month of the change | €15 |
| G1Q | Change of company name | Filed with the special resolution | €50 |
| G1 | Special resolution (other than a name change) | Within 15 days of being passed | Free |
B1 annual return
Every company files a B1 each year, made up to its annual return date. A new company's first annual return date is six months after incorporation. Our guide to annual return (B1) deadlines covers the detail.
B10 change of directors or secretary
File a B10 within 14 days of any change to your directors or secretary. It must be signed by a current officer of the company. Failing to file is an offence.
B2 change of registered office
If your registered office moves, file a B2 within 14 days. It is free online.
B5 return of allotments, and B7, G1Q and special resolutions
Issuing new shares means a B5 within one month. Changing the share structure needs a B7. Changing your name needs a special resolution and Form G1Q, and other special resolutions must be delivered within 15 days of being passed.
CRO penalties and enforcement
Missing a CRO deadline costs more than a late fee:
- Late fees. A late B1 attracts a €100 late fee plus €3 a day, capped at €1,200 per return.
- Loss of audit exemption. Since 16 July 2025, a company that files its annual return late more than once in five years loses audit exemption for the following two years.
- Involuntary strike-off. The CRO can strike off a company that fails to file an annual return, fails to meet the EEA-resident director requirement, has no directors on record, or is reported by Revenue for a missing statement.
- Director consequences. Once a company is struck off, it loses limited liability protection, its assets pass to the State, and its directors can face disqualification proceedings.
Filing with the CRO in practice
Most filings are made online through CORE. Registering for a CORE account is free, and it lets you file, track filings and get notifications about status changes.
Small mistakes cause many rejected filings: a resigned director signing a B10, missing details, or dates that don't match the company's records. If a returned annual return isn't corrected within 14 days, the resubmission is treated as a new filing and can attract late fees.
That is why many founders hand CRO filings to a company secretary service. If you only need the annual return handled, our CRO B1 filing service covers it.
Frequently Asked Questions
What is the CRO in Ireland?
In answer to what is CRO: it is the Companies Registration Office, the State body that incorporates companies, registers business names and receives the filings companies must make after incorporation. It sits under the Department of Enterprise, Tourism and Employment. It also enforces filing rules under the Companies Act 2014 and makes company information available to the public.
What is a CRO number?
On what is a CRO number Ireland: it is the unique registration number the Company Registration Office gives your company when it is incorporated. You'll use it on bank forms, tax registrations and all later CRO filings.
How do I do a CRO search?
To search the Ireland company register, go to CORE, the CRO's online system, and search by company name or registered number. You'll see its basic public details and the documents it has filed. A CRO search of basic details is quick, while copies of filed documents cost €2.50 each and a printout of basic company details costs €3.50.
What forms does a company have to file with the CRO?
Every company files a B1 annual return each year. Event-driven forms include the B10 for officer changes and the B2 for a registered office move, both within 14 days. The B5 for new shares is due within one month. Name changes and special resolutions need G1Q or G1 filings. CRO Ireland fees for most of these are low or free online.
What does "strike off listed" mean on the CRO?
It usually means the CRO has published a notice that the company is due to be struck off, often for a missing annual return. The company is struck off 28 days after that notice unless the outstanding filings are made first. File the missing returns quickly.
Keep your company in good standing
You can hand all your CRO filings to us and get on with running the business. If you are just starting out, click here to price your company formation. Once you are trading, our bookkeeping packages keep your accounts ready for every annual return.