How to Register as a Sole Trader in the UK (2026)
Here’s the bit that surprises most people: you can legally start trading as a sole trader tomorrow, without filling in a single form. There’s no licence to apply for, no approval to wait on. The catch is that HMRC still needs to know you exist u2014 and there’s a real deadline for telling them, one that’s easy to lose track of if you’re busy actually running a business.
At Filing Accounts, we help newly self-employed people register correctly and get their first Self Assessment return sorted without the last-minute panic.
Do You Actually Need to Register?
Only if your gross self-employment income goes over £1,000 in a tax year (6 April to 5 April). Under that, you’re covered by the trading allowance and there’s genuinely nothing to do u2014 no registration, no return, no tax. It’s worth registering anyway even below that threshold if you want a UTR for something like a mortgage application or business bank account, but it’s not compulsory.
Over £1,000, registration stops being optional. This applies whether self-employment is your whole income or something you’re doing on the side of a regular job u2014 there’s no exemption for side hustles, and HMRC treats a Saturday market stall the same way it treats a full-time consultancy.
The Deadline: 5 October, Not 31 January
This is where people get confused, because there are genuinely two different deadlines involved and they’re easy to mix up. Registering as self-employed is due by 5 October following the end of the tax year you started trading in u2014 not the 31 January most people associate with tax returns, which is actually the filing deadline that comes later.
Worked example: say you started freelancing in July 2025. That falls in the 2025/26 tax year, so you need to register by 5 October 2026 u2014 and your first Self Assessment return, covering that same period, isn’t due until 31 January 2027. It sounds like a long runway, but it goes faster than you’d think, especially if you’re not tracking your income from day one.
Missing the October registration deadline itself doesn’t always trigger an instant fine u2014 but missing the January filing deadline that follows it absolutely does, starting at £100 and adding daily charges the longer it drags on.
How to Actually Register
The whole thing happens on GOV.UK, and it’s genuinely quick u2014 most people are done in 10 to 15 minutes.
Before You Start, Have Ready:
- Your National Insurance number
- A Government Gateway account (you can create one as part of the process if you don’t have one)
- Your full name and address
- The date you actually started trading
- A one-line description of what you do u2014 “freelance graphic designer” or “plumber” is genuinely all that’s needed
- An email address you actually check, since HMRC sends some confirmations digitally
When the form asks how you want to register, choose “sole trader” u2014 not “partner” (that’s for business partnerships) and not “not self-employed” (that route is for people registering for other reasons, like reporting rental income).
Then You Wait u2014 and This Is the Part to Plan Around
Once you’ve registered, HMRC posts your UTR u2014 usually within about 10 working days, though it’s sensible to allow 3 to 4 weeks before you’ve got everything fully set up and can see your Self Assessment account properly online. This is exactly why registering the moment you start trading, rather than waiting, saves you a headache later: if you leave it until September for an October deadline, a slow post day can genuinely put you at risk.
Already Employed? You Can Still Do This
Yes, you can be employed and self-employed at the same time, and it’s more common than people assume u2014 the classic case is someone working 9-to-5 who also freelances or sells things on the side. You generally don’t need to tell your employer (unless your contract specifically requires it), and your PAYE tax code at your main job usually carries on as normal. Your employed income keeps getting taxed at source as always; your self-employed income gets reported separately through Self Assessment, and the two systems talk to each other when HMRC works out your overall tax position.
What If You’ve Registered Before and Stopped?
If you were self-employed previously, told HMRC you’d stopped, and now you’re starting again, don’t create a brand new registration u2014 it’s tempting, but it can generate duplicate records that take HMRC months to untangle. Instead, sign back in with your existing details and reactivate your Self Assessment record. If that option isn’t showing online, a phone call to HMRC or Form CWF1, specifically stating you’re restarting, sorts it out.
What Happens After You’re Registered
- You’ll file a Self Assessment return every year by 31 January, declaring your income and expenses
- You’ll pay Income Tax on your profits at the same rates as employees u2014 see our full UK tax rates guide
- You’ll also pay Class 4 National Insurance on profits above the threshold
- You only need to think about VAT if your turnover crosses £90,000 in a rolling 12 months u2014 see our VAT registration guide
- You can start claiming allowable business expenses against your income
A Few Honest Warnings From People Who’ve Been There
Income tax isn’t deducted at source when you’re self-employed u2014 nobody does it for you the way an employer does through PAYE. Set aside a chunk of every payment as it lands, rather than spending it all and scrambling in January. Many sole traders find putting aside somewhere around a quarter to a third of what comes in gives them a comfortable buffer, though your own figure depends on your profit level and tax band.
And write your UTR down somewhere safe the moment it arrives. You’ll need it every single year, and while HMRC can help you recover it if it’s lost, it takes time you won’t want to spend when a deadline’s approaching.
Common Mistakes to Avoid
Confusing the Registration and Filing Deadlines
5 October is for telling HMRC you exist; 31 January is for filing the actual return. Mixing them up is one of the most common early mistakes.
Registering as a “Partner” by Mistake
If you’re working alone, not in a formal partnership, choose “sole trader” u2014 the partner route is for a different registration entirely.
Creating a Duplicate Registration When Restarting
If you’ve been self-employed before, reactivate your old record instead of registering fresh u2014 duplicates cause real delays to sort out.
Waiting Until September to Register
With a 10-working-day wait for your UTR by post, cutting it close to the October deadline leaves very little margin for anything to go wrong.
Frequently Asked Questions
Do I need to register if I earn under £1,000 self-employed?
No u2014 the trading allowance covers this, and there’s nothing to register or report.
How much does it cost to register as a sole trader?
Nothing. Registering directly with HMRC is completely free u2014 you never need a paid formation agent or third-party registration service.
How long does it take to get my UTR?
Usually around 10 working days by post, though allowing 3 to 4 weeks is sensible before everything’s fully set up online.
Can I be employed and register as a sole trader at the same time?
Yes. Your PAYE job and your self-employment are reported and taxed separately, and you generally don’t need to tell your employer.
What if I’ve been a sole trader before and I’m starting again?
Reactivate your existing Self Assessment record rather than registering as new, to avoid creating duplicate HMRC records.
Just Starting Out? Talk to Filing Accounts UK
Getting registered correctly, and knowing what’s coming next, makes the first year of self-employment far less stressful. At Filing Accounts, we help newly self-employed people register, understand their obligations, and file their first Self Assessment return with confidence.
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