Starting a side hustle, freelancing, or launching a business means registering as self-employed with HMRC. The process is straightforward but getting it right from the start saves headaches later.
When You Must Register
You need to register as self-employed if you earn more than £1,000 from self-employment in a tax year. Below that threshold, the trading allowance covers your income automatically.
The legal deadline is 5 October in your second tax year of trading. If you started in June 2026, the deadline would be 5 October 2027. However, registering early is strongly recommended — late registration can trigger penalties and means you miss NI contribution credits.
What Counts as Self-Employment
You’re self-employed if you:
- Run your own business as a sole trader
- Work as a freelancer or contractor
- Sell goods or services regularly for profit
- Earn rental income (in some cases)
Occasional one-off sales (a car boot sale, selling old belongings) generally don’t count, but regular selling on platforms like eBay or Etsy does once you exceed the trading allowance.
Step-by-Step Registration
Step 1 — Create a Government Gateway Account
Visit gov.uk and create your Government Gateway user ID if you don’t already have one. You’ll need:
- Your National Insurance number
- An email address
- A UK mobile phone number for two-factor authentication
Step 2 — Register for Self Assessment
Once logged in, select “Register for Self Assessment” and choose “Self-employed” as the reason. You’ll enter:
- Your full name and address
- National Insurance number
- Business name (or your own name if trading under your personal name)
- Business type and description (e.g., “graphic design services”)
- The date you started self-employment
Step 3 — Receive Your UTR Number
HMRC will post your Unique Taxpayer Reference (UTR) to your registered address within 10 working days. This 10-digit number is your tax identity for Self Assessment.
Keep your UTR safe — you’ll need it for:
- Filing your annual tax return
- Mortgage and loan applications
- Opening business bank accounts
- Working with an accountant
Step 4 — Set Up Your Records
From day one, keep records of:
- All income — invoices, bank transfers, cash payments
- All business expenses — receipts, subscriptions, mileage
- Bank statements — ideally a separate business account
HMRC can ask to see records going back 5 years, so establish good habits immediately.
National Insurance When Self-Employed
Registering triggers two types of NI:
| Class | Rate (2026/27) | When You Pay |
|---|---|---|
| Class 2 | £3.45 per week | Profits above £12,570 (collected through Self Assessment) |
| Class 4 | 6% on £12,570–£50,270; 2% above | Collected through Self Assessment |
Class 2 NI is important because it counts towards your State Pension entitlement. Even if your profits are low, you can pay voluntary Class 2 contributions to protect your pension record.
Common Registration Mistakes
Registering Late
If you miss the 5 October deadline, HMRC can charge penalties starting at £100. The longer you delay, the higher the penalties — plus you may face interest on any tax owed.
Not Separating Business and Personal Money
While not a legal requirement, opening a separate business bank account makes bookkeeping dramatically easier and helps if HMRC ever investigates.
Forgetting About Making Tax Digital (MTD)
From April 2026, self-employed people with income over £50,000 must keep digital records and submit quarterly updates to HMRC through Making Tax Digital for Income Tax. The threshold drops to £30,000 from April 2027.
Not Budgeting for Tax
HMRC doesn’t deduct tax automatically from self-employed income. Set aside 25-30% of profits in a separate savings account for your tax bill. Your first bill may include payments on account (advance payments towards next year’s tax).
Registering a Partnership or Limited Company
If you’re working with someone else, you might register a partnership instead of being a sole trader. Both partners must register individually for Self Assessment, and you’ll also need a partnership UTR.
If you’re setting up a limited company, the process is different — you register with Companies House rather than as self-employed. You’ll still need to register for Self Assessment if you’re a company director receiving a salary and dividends.
What Happens After Registration
Once registered, your annual obligations are:
- Keep accurate records throughout the year
- Submit quarterly MTD updates (if above the threshold)
- File your Self Assessment tax return by 31 January following the end of the tax year
- Pay your tax bill by 31 January (with a possible second payment on account by 31 July)
The first tax return covers from your start date to 5 April. If you register partway through a year, you only report income from when you started trading.
Deregistering
If you stop being self-employed, notify HMRC within the same tax year or when filing your final Self Assessment. You can deregister online through your Government Gateway account. File a final tax return covering the period up to when you stopped trading.