Last updated: 2 September 2026
A plain-English guide from The Company Shop, Northern Ireland’s company formation specialists since 1994.
What is Companies House Belfast?
Companies House Belfast is the Northern Ireland office of Companies House, the UK registrar of companies. Every limited company, LLP and other registered entity with a registered office in Northern Ireland is incorporated and filed through Companies House, and the Belfast office is the local presence for those companies.
Before October 2009, Northern Ireland had its own registry — the Companies Registry within the Department of Enterprise, Trade and Investment. When the Companies Act 2006 was extended to Northern Ireland, the registry became part of Companies House. That is why older NI companies sometimes have paperwork referring to “DETI Companies Registry” and why Northern Ireland company numbers look different from English, Welsh and Scottish ones.
Where is Companies House in Belfast?
The Belfast office is at Second Floor, The Linenhall, 32–38 Linenhall Street, Belfast BT2 8BG — in the city centre, a few minutes’ walk from City Hall.
Public counter arrangements have changed over recent years and most filings are now made online, so if you are planning to visit in person, check the current opening arrangements on GOV.UK first. Postal filings for Northern Ireland companies should also be sent to the Belfast address rather than to Cardiff or Edinburgh.
What does the Belfast office do?
In practice Companies House operates as one UK-wide registrar, so the Belfast office handles the same functions as Cardiff and Edinburgh for companies registered in Northern Ireland:
- Incorporating new Northern Ireland companies and LLPs
- Receiving confirmation statements, annual accounts and changes to directors, addresses and shareholdings
- Maintaining the public register, which anyone can search free of charge
- Striking off companies that stop filing, and restoring dissolved companies to the register
- Processing identity verification for directors and people with significant control
Northern Ireland company numbers explained
A company registered in Northern Ireland has a company number beginning with NI followed by six digits — for example NI012345. Other prefixes you may see for Northern Ireland entities include NC (limited liability partnerships), NF (overseas companies with an NI establishment) and NP (some older or specialist registrations). A company number starting with a digit is registered in England and Wales; SC means Scotland.
The prefix follows the company for life. If you move a Northern Ireland company’s registered office, it must stay in Northern Ireland — a company cannot move its registered office between the three UK jurisdictions without re-registering.
Searching the Companies House register
The full register is free to search at find-and-update.company-information.service.gov.uk. You can check whether a company name is already in use, see who the directors are, download filed accounts and see whether a company is active, dormant or dissolved. If you are choosing a name for a new Northern Ireland company, the company name check on our homepage uses the same data and flags names that are too similar to existing ones or contain sensitive words.
Filing for a Northern Ireland company
Almost everything can be filed online through Companies House WebFiling or an authorised agent. The filings every NI company must make are:
- Confirmation statement — at least once every 12 months, confirming the company’s details are up to date. Our confirmation statement filing service handles this for you.
- Annual accounts — within nine months of the financial year end for a private company.
- Changes — new or resigning directors, a new registered office, changes to people with significant control, and share allotments, each within the statutory deadline.
Miss the confirmation statement or accounts and Companies House will first write to the registered office, then begin the process of striking the company off. If that has already happened, see our guide to restoring a dissolved Northern Ireland company.
Identity verification for NI directors
Since November 2025, every director and person with significant control must verify their identity with Companies House. New directors verify before appointment; existing directors verify by the date of their company’s next confirmation statement in the 12 months to 18 November 2026. Verification can be done through GOV.UK One Login or through an Authorised Corporate Service Provider (ACSP). The Company Shop is a registered ACSP based in Belfast and can verify directors and PSCs online or in person.
Frequently asked questions
Can I register a company at the Belfast office in person?
Incorporations are made online or by post. Most people use an agent or the online service; there is no walk-in incorporation counter.
Is Companies House Belfast the same as the Companies Registration Office (CRO)?
No. The CRO in Dublin is the registrar for the Republic of Ireland. A company registered with the CRO is an Irish company; a company registered at Companies House Belfast is a UK company with a Northern Ireland registered office. Irish businesses that want a UK entity usually form a Northern Ireland company with a Belfast registered office.
How do I contact Companies House Belfast?
Companies House runs a single UK contact centre for all three offices. Contact details and current opening hours are on GOV.UK. If you would rather talk to someone locally about a Northern Ireland company, our Belfast team can help with formations, filings, registered office and restorations — get in touch.
Need help with a Northern Ireland company?
The Company Shop has formed more than 22,000 companies from our Belfast office since 1994. Whether you are setting up a new NI company, need a Belfast registered office, or have a filing problem to untangle, call us on 028 9055 9955 or send a message.
This article is for general information only and reflects the position as at the date of publication. It does not constitute legal, accounting or professional advice and should not be relied upon as such. Fees, rules and deadlines may change. You should seek advice from a suitably qualified professional before acting on anything covered here.