Do I need to register as self-employed in the UK?

You can start working for yourself tomorrow without telling anyone. Nobody checks. But if you do need to register as self-employed in the UK, there's a deadline, and it's earlier than most people think. Here's how to tell if it applies to you.

Do I need to register as self-employed?

GOV.UK's sole trader guidance says you can start trading without registering first. It also says you must register for Self Assessment if you earn more than £1,000 in a tax year. The tax year runs from 6 April to 5 April.

So the rule isn't about a job title. It's about income. The £1,000 is your gross trading income, which means what customers paid you before you take off any costs. GOV.UK's page on tax-free allowances on trading income gives the same £1,000 figure, and says you register by 5 October in the following tax year.

I wrote about how that allowance works in the trading allowance explained.

How do I know if I'm "trading"?

GOV.UK's working for yourself page lists signs that you're running a business. You might be if you:

• sell regularly to make a profit
• make items to sell for profit
• sell regularly online, at car boot sales or through classified adverts
• are paid for a service you provide

It also lists signs of being in business: you take responsibility for its success or failure, you have several customers at once, you decide how, where and when you work, and you charge an agreed fixed price.

You can be employed and run a business at the same time. A teacher who tutors on Saturdays is still trading. If you only sell the odd item or rent out property now and then, GOV.UK says to check whether you need to tell HMRC about that income. If you're unsure, it says to contact HMRC.

When is the deadline to register?

For the tax year 6 April 2025 to 5 April 2026, GOV.UK's register for Self Assessment page says you must tell HMRC by 5 October 2026. That date has now passed.

If you started earning from self-employment last year and haven't registered, don't wait for January. Register now. The page says telling HMRC after 5 October 2026 could result in a penalty.

The same rule repeats every year. Earn over £1,000 between 6 April 2026 and 5 April 2027, and your deadline is 5 October 2027.

What happens if I register late?

GOV.UK's Self Assessment penalties page says that if you register after 5 October and don't pay your whole tax bill by 31 January, you may get a "failure to notify" penalty. It's based on the amount of tax still unpaid.

Note the order. The penalty depends on unpaid tax. If you register late but pay what you owe on time, you're in a much better position than someone who waits and pays late too.

Late filing is a separate penalty. The same page says the initial penalty is £100. After three months it's £10 a day, up to £900. After six months there's another penalty of 5% of the tax due or £300, whichever is higher. After 12 months, the same again.

How do I register?

1. Check whether you need to send a tax return, using the checker linked on the register for Self Assessment page.
2. Register online through the "Start now" link on that page.
3. Wait for your Unique Taxpayer Reference (UTR) from HMRC. GOV.UK links to separate guidance on when to expect it.
4. Send your tax return. After you register, GOV.UK says you must submit Self Assessment returns.

If you registered in the past but didn't need to send a return last year, you may have to reactivate your account. The online service explains how.

What else changes when you register?

Registering means HMRC works out your Income Tax and National Insurance from your profits when you submit your return, according to the sole trader page.

On National Insurance, GOV.UK's self-employed rates page says that for 2026 to 2027, Class 2 is treated as paid once profits reach £7,105. Class 4 is 6% on profits from £12,570 up to £50,270, and 2% above that. These are the figures on the page today, so check it again when you file.

Two more things to do from day one. Keep records from the day you start trading, as the sole trader page says. I've covered how in how to keep records when you're self-employed. And if your income grows, check the VAT rules too.

My take

Most people I talk to aren't avoiding registration. They just don't know the date. 5 October sits in a quiet part of the year, three months before the January deadline everyone knows.

My advice is simple. If you've made even a few hundred pounds from your own customers this year and think you might pass £1,000, register early. It costs nothing, and you can do it in one evening.

At Vcents, we help you get paid through WhatsApp with a bank payment link. It also gives you a clear record of what came in, which makes that first return a lot less painful.

Sources

• GOV.UK: Register for Self Assessment (checked 19 October 2026)
• GOV.UK: Set up as a sole trader (checked 19 October 2026)
• GOV.UK: Tax-free allowances on property and trading income (checked 19 October 2026)
• GOV.UK: Working for yourself (checked 19 October 2026)
• GOV.UK: Self Assessment tax returns penalties (checked 19 October 2026)
• GOV.UK: Self-employed National Insurance rates (checked 19 October 2026)