How to Start a Company in the UK — Step by Step Guide 2026

1. Choose your company structure

The vast majority of new UK companies are registered as private limited companies (Ltd). This gives you limited liability — meaning your personal assets are protected if the business runs into trouble. Other options include LLPs (for partnerships) and PLCs (for companies that want to sell shares publicly).

Not sure which is right? Read our Ltd vs Sole Trader comparison or full guide to UK company types.

2. Pick your company name

Your company name must be unique on the Companies House register. You can search existing companies on BizLookup to check availability instantly. Names cannot contain sensitive words (like "Royal", "British" or "Authority") without permission, and must end in "Limited" or "Ltd".

Also search the UK Trademark Register to avoid infringing existing trademarks — Companies House will register your name even if a trademark exists.

3. Prepare your details

Before registering, you need:

• Registered office address — a UK address that will be publicly visible on the Companies House register. This does not need to be where you work; many directors use their accountant's address or a registered office service.
• At least one director — must be aged 16 or over. Directors' names, dates of birth and addresses are filed publicly (residential addresses can be protected using a service address).
• At least one shareholder — can be the same person as the director. You need to decide on share structure (most simple companies issue 1 ordinary share of £1).
• SIC code — a 5-digit code that describes your business activity. You can find the full list on the Companies House website.
• Articles of association — the rules governing how your company is run. Most companies use the Model Articles provided by Companies House.

4. Register with Companies House

You can register online at gov.uk/set-up-limited-company. The fee is £12 for online registration, and approval typically takes 24 hours. Paper applications cost £40 and take 8-10 days.

Once approved, you will receive a Certificate of Incorporation with your unique company number and the date your company was legally formed. You can then look up your new company on BizLookup to verify the details are correct.

5. Register for Corporation Tax

Within 3 monthsof starting to trade, you must register for Corporation Tax with HMRC. This is separate from Companies House. You will need your company's UTR (Unique Taxpayer Reference) which HMRC posts to your registered office shortly after incorporation.

The current Corporation Tax rate is 25% on profits over £250,000, with a small profits rate of 19% for companies with profits under £50,000. Use the CalcPad Corporation Tax Calculator to estimate your liability.

6. Set up a business bank account

Limited companies must have a separate business bank account — you cannot use a personal account. High street banks like Barclays, Lloyds and NatWest offer 12-18 months free business banking. Digital-first options like Starling Business, Tide and Mettle offer free accounts with no monthly fee.

7. Understand your ongoing obligations

Once incorporated, you must file:

• Annual accounts — due 9 months after your accounting reference date. Read our annual accounts guide.
• Confirmation statement — an annual check-in with Companies House confirming your company details are correct. Costs £13 online.
• Corporation Tax return (CT600) — due 12 months after your accounting period ends.
• VAT returns — if your turnover exceeds £90,000 you must register for VAT. See our VAT registration guide.

8. Consider VAT registration

You must register for VAT if your taxable turnover exceeds £90,000 in any rolling 12-month period (2025/26 threshold). You can register voluntarily below this threshold, which can be beneficial if your customers are VAT-registered businesses (they can reclaim the VAT you charge). Use the CalcPad VAT Calculator to work out the numbers.

Common mistakes to avoid

• Not keeping company and personal finances separate — mixing accounts can "pierce the corporate veil" and remove your limited liability protection.
• Missing filing deadlines — Companies House issues automatic penalties. Late accounts cost £150 (rising to £1,500 if more than 6 months late).
• Forgetting to register for Corporation Tax — HMRC can charge penalties and interest on late registration.
• Using your home address without understanding it is public — your registered office address appears on the public register. Consider a service address.
• Not getting proper insurance — professional indemnity, public liability and employers' liability (if you hire) should be sorted before you start trading.

Costs summary