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If you have earned more than £1,000 from working for yourself in a tax year, HMRC needs to hear from you. Registering is free, you do it online, and the process itself takes about ten minutes. The part people get wrong is everything around it: the deadline, what your Unique Taxpayer Reference actually does, and the tax that lands months later. This guide give the answer how to register as self-employed and the bits gov.uk leaves you to work out on your own.
We register sole traders every week from our offices in Tooting and Barking, so the order below is the order that avoids the avoidable penalties.
Do you need to register as self-employed?
Yes, if you earned more than £1,000 from self-employment in a single tax year, which runs from 6 April to 5 April. That £1,000 figure is the trading allowance. Earn under it and you can usually keep the income without telling HMRC. Go over it, even by a pound, and you must register for Self Assessment as a sole trader.
You can also register before you cross £1,000 if you want to. Some people do it early to reclaim VAT, to start building a National Insurance record, or simply because they would rather not track a threshold all year.
You can start trading the day you decide to. Registration is a tax formality, not a permit. The income clock and the record-keeping start from your first sale, so keep every invoice and receipt from day one.
How to register as self-employed with HMRC
Registration happens through your Government Gateway account and the Self Assessment service. The steps:
- Set up a Government Gateway user ID if you do not already have one. You will use it for every tax task from here on, so store the details somewhere you will find them in January.
- Sign in and start the Register for Self Assessment service, choosing the self-employed or sole trader option. This route uses form CWF1 behind the scenes.
- Give HMRC your personal details, the date you started trading, and a plain description of the work you do.
- Submit HMRC then sets up your Self Assessment record and issues your Unique Taxpayer Reference.
One correction worth making, because it trips people up: form SA1 is not the one you want. SA1 is for people who need Self Assessment but are not self-employed, such as landlords or those with untaxed investment income. As a sole trader you register through the self-employed route, which is CWF1. Pick the wrong one and your record can be set up without the self-employment element, which means your National Insurance does not flow correctly.
If a limited company suits you better than a sole trader, the registration path is different. Our guide to forming a limited company covers that route and the tax that comes with it.
The registration deadline you cannot miss
You must tell HMRC by 5 October following the end of the tax year in which you started.
Put dates to it. If you started working for yourself at any point during the 2025/26 tax year, which ended on 5 April 2026, your deadline to register is 5 October 2026. Miss it and a penalty can follow, on top of any tax due.
The deadline catches people who start in spring and assume they have until the January filing date to sort everything out. Registering and filing your Self Assessment return are two separate jobs with two separate deadlines. Register first, file later.
Getting your UTR and activating your account
After you register, HMRC posts your ten-digit Unique Taxpayer Reference to your address. This is the number that identifies you for every Self Assessment return, payment, and call from now on.
HMRC no longer publishes a fixed “arrives within X days” figure for the UTR, so ignore any guide that still quotes ten working days. Timing moves with their workload. Check the current estimate using HMRC’s own “when you can expect a reply” tool, and allow longer if you live abroad.
If you started late and the post is slow, register anyway and keep the confirmation. What matters for the deadline is that you registered in time, not that the UTR has landed.
What you will pay: Income Tax and National Insurance
Registering does not trigger a bill straight away. HMRC works out what you owe from your first Self Assessment return, based on your profit, which is your income minus your allowable expenses.
National Insurance is where outdated guides do the most damage, so here are the verified 2026/27 rules, drawn from the self-employed National Insurance rates.
Class 2 is no longer a flat weekly charge that every sole trader pays. For 2026/27, if your profits are £7,105 or more, your Class 2 contributions are treated as paid and you pay nothing for them. If your profits fall below £7,105, Class 2 becomes voluntary, charged at £3.65 a week, and you might still choose to pay it to protect your State Pension record.
Class 4 applies once profits pass £12,570. For 2026/27 you pay 6% on profits between £12,570 and £50,270, then 2% on anything above £50,270. Most sole traders pay both Class 4 and their Income Tax through the same Self Assessment return.
Income Tax then applies at the usual rates on profit above your personal allowance.
What happens after you register
Three things tend to surprise first-year sole traders.
Your first tax bill can be larger than the tax alone, because HMRC may ask for a payment on account, an advance toward next year’s bill, alongside what you owe. Set money aside for it rather than meeting it cold in January. Our tips on keeping cash flow healthy as a sole trader help here.
Making Tax Digital for Income Tax is arriving. From 6 April 2026, sole traders with qualifying income over £50,000 must keep digital records and send quarterly updates to HMRC instead of one annual return. If your turnover is near that line, set up compatible software now rather than later.
Record keeping is a legal requirement, not a nicety. You will lean on those records for your first return, so keep them for at least the period HMRC requires.
Registering when you are also employed
You can be employed and self-employed at the same time, and plenty of people are. Your employer handles PAYE on your salary. You handle Self Assessment on your self-employed profit. The two sit side by side, and our guide to paying tax as a freelancer covers how they combine.
Register for self-employment through the same CWF1 route even if you already have a PAYE record. Your Self Assessment return then pulls both income sources together so HMRC taxes you once, correctly, across the lot.
How much does it cost to register?
Nothing. Registering with HMRC is free, whether you do it online or by post. The only cost is optional: paying an accountant to register you, set your record up cleanly, and take the Self Assessment off your plate each year. For a straightforward sole trader that is a choice, not a requirement.
When it is worth getting an accountant
If your situation is simple, a salaried side hustle, modest profit, no VAT, you can run Self Assessment yourself. Talk to an accountant when the picture gets more involved: you are near the VAT or MTD thresholds, you are juggling employment and self-employment, you have property income in the mix, or you simply want the return done right the first time. Getting the structure correct in year one saves unpicking it later. If that is you, speak to our Tooting and Barking team.
Frequently Asked Questions
Do I need to register as self-employed?
You must register if you earned more than £1,000 from self-employment in a tax year, which runs from 6 April to 5 April. Below £1,000 the trading allowance usually covers it. You can choose to register earlier if you prefer.
How long does it take to register?
The online registration itself takes about ten minutes. HMRC then posts your Unique Taxpayer Reference separately. Timing for the UTR varies, so check HMRC’s “when you can expect a reply” tool rather than relying on a fixed number of days.
How much does it cost to register as self-employed?
It is free to register with HMRC. You only pay if you choose to use an accountant to handle the registration and your Self Assessment.
What is the deadline to register?
You must register by 5 October following the end of the tax year you started trading. For someone who started in the 2025/26 tax year, that deadline is 5 October 2026.
Can I register if I am employed and self-employed at the same time?
Yes. PAYE covers your employment income and Self Assessment covers your self-employed profit. You register for self-employment through the CWF1 route and report both on one return.
What National Insurance will I pay?
For 2026/27, Class 2 is treated as paid at no cost if your profits are £7,105 or more, and is voluntary at £3.65 a week below that. Class 4 is 6% on profits from £12,570 to £50,270 and 2% above £50,270.
Muhammad Sufyan Moavia
Muhammad Sufyan Moavia, Chartered Tax Adviser and Fellow Chartered Certified Accountant at IBISS & CO.
He has 15 years experience in accounting and tax, advising individuals and business owners on personal tax, HMRC matters, IHT, CGT and tax planning.
Last review: July 2026
