How to set up a limited company in the UK (step-by-step)

Setting up a limited company sounds like paperwork and lawyers. It isn’t. You can register online with Companies House in under an hour, and most people do it themselves. Here’s exactly how.

Before you start: is a limited company right for you?

A limited company is a separate legal “person” from you. That means your personal finances are protected if the business runs into trouble (limited liability), and it can be more tax-efficient once you’re earning a decent profit. The trade-off is more admin — annual accounts, a confirmation statement, and Corporation Tax.

If you’re just testing an idea or earning a little on the side, being a sole trader is simpler. We compare the two in detail in sole trader vs limited company.

What you’ll need

• A company name that isn’t already taken (check the Companies House register first)
• A registered office address (this becomes public — many people use their accountant’s address or a service address for privacy)
• At least one director (that’s you)
• At least one shareholder (also usually you)
• Details of who has significant control (usually the same person)
• Your SIC code — a standard code describing what your business does

The steps

1. Choose and check your name. It must be unique and not too similar to an existing company.
2. Go to GOV.UK and use the official “Register a limited company” service. Avoid the third-party sites that charge extra for the same thing.
3. Enter your details — directors, shareholders, address, SIC code.
4. Pay the registration fee (a small one-off charge — check gov.uk for the current amount) and submit.
5. Wait for approval — often within 24 hours. You’ll get a Certificate of Incorporation with your company number.

That’s it. You’re a company.

The day after: the bit people forget

Registering is the easy part. Running the thing is where it gets real. In your first week you should:

• Open a business bank account — keep company money separate from personal from day one.
• Register for Corporation Tax with HMRC (within 3 months of trading).
• Start tracking every penny in and out. This is not optional — your year-end accounts depend on it, and so does knowing whether you’re actually making money.

That last point is where most new founders come unstuck: they’ve got a company, but no system. Receipts in a shoebox, invoices in a notes app, no idea what the profit actually is.

That’s exactly what Sedonis is for — invoices, expenses, profit and P&L in one private place, from your very first sale. It’s free to start, and it means when your accountant asks for the numbers at year-end, you just have them.

---

This is general information, not financial or legal advice. Check GOV.UK and speak to an accountant for your specific situation.