A Checklist for Registering Your Startup at Companies House

Incorporating a UK limited company is mechanically simple. The IN01 form takes around 30 minutes to complete online, costs £50, and is processed by Companies House within 24 hours. The reason it is worth thinking carefully about is that several of the choices made on the form persist for the life of the company. This guide walks through the full checklist with the decisions that matter flagged explicitly.

Step 1: Pick the company name

The name must be unique on the Companies House register, must end in "Limited" or "Ltd" (some technicalities aside), and cannot include sensitive words ("bank", "royal", "British", and others) without specific permission. Beyond those constraints, the choice is yours.

Things to check before locking in a name:

• Is the name available on the Companies House register? Use companies-house.gov.uk's name availability search.
• Are the matching domains available (.co.uk and .com at minimum)? Brand without domain is brittle.
• Is the trademark available? Search the IPO trademark register for similar marks in your trading class.
• Does the name have international resonance, or only domestic? US expansion is significantly harder with a name that means something different in American English.
• Will the name still fit if the product pivots? Generic-but-flexible often beats specific-but-pinned-down.

Step 2: Choose the registered office address

The registered office is where Companies House and HMRC send official correspondence. It is also a public record on the Companies House register. The address must be in the UK and must be a real address where mail can be received.

Three viable options:

• Home address. Free but public. Anyone can search by company name and find it.
• Registered office service from a formation agent or accountant. £30 to £100 per year, includes mail forwarding.
• Co-working or serviced office that includes a registered office address. £150 to £400+ per month, includes a real workspace.

Step 3: Director appointments

List all initial directors. For most startups this is the founders. Each director needs to provide their full name, date of birth, occupation, nationality, and service address (which can be different from the residential address shown on the form). The residential address is collected by Companies House but is not displayed publicly; the service address is.

Director appointments come with legal duties under the Companies Act 2006. Anyone agreeing to be a director of your company should understand they take on personal obligations including duty of care, duty to promote the success of the company, and a duty to avoid conflicts of interest. If your co-founder is hesitant about being a director, do not push past their hesitation; it usually reflects something worth understanding.

Step 4: Persons with Significant Control (PSC) register

The PSC register identifies anyone who, broadly:

• Holds more than 25% of the shares.
• Holds more than 25% of the voting rights.
• Has the right to appoint or remove a majority of directors.
• Has the right to exercise (or actually exercises) significant influence or control.

For a typical two-founder startup with a 50/50 split, both founders are PSCs (each holds more than 25%). The information is published on the public register. Failing to register a PSC accurately, or failing to update it when ownership changes, is a criminal offence carrying fines for the company and the directors personally.

Step 5: Share capital and share allocation

The IN01 asks for the initial share capital: how many shares, of what class, with what nominal value, allocated to whom. For a typical startup, "100 ordinary shares of £0.01 each" is a clean default that gives flexibility for future share issues. Some founders pick larger numbers (1,000 or 10,000) for the same flexibility; both work.

The allocation between co-founders is the more important decision. 50/50 splits are common but not always right. The key consideration is that whatever split you pick, it should be combined with vesting and a shareholders agreement. We cover the share-issuance question in detail in the dedicated spoke on issuing shares to co-founders and employees.

Step 6: Articles of association

The articles of association are the company's constitution. They govern share rights, director appointments, decision-making procedures, and shareholder meetings. Companies House provides default "model articles" which you can adopt at incorporation by ticking the relevant box.

Model articles are adequate for simple single-shareholder companies. They are inadequate for any company that will:

• Have multiple share classes (which most investor rounds require).
• Need pre-emption rights, drag-along, or tag-along provisions.
• Have specific director appointment rights (e.g., an investor director).
• Need vesting structures embedded in the share rights.

If investment is on the horizon, draft bespoke articles at incorporation. Cost: £200 to £600 from a startup-specialist accountant or solicitor. Cheaper than amending model articles later under investor pressure during a deal.

Step 7: Submit and verify

Submit the IN01 online via Companies House Web Filing or via a formation agent. Pay the £50 fee. Within 24 hours you receive a Certificate of Incorporation, the company's unique company number, and confirmation that the company exists.

Immediately after incorporation, save copies of: the certificate of incorporation, the IN01 you submitted, the memorandum of association, and the articles of association. These are the foundation documents for every future investor due diligence.