Becoming self-employed is less about registering a business and more about changing how you handle money, records and deadlines. The UK tax system doesn’t send you a payslip — you have to work out what you owe, tell HMRC, and pay on time. Most people who get into trouble in their first year don’t owe a lot of tax; they just missed a deadline or didn’t keep the right records.
This is the hub. Each section below covers one thing you need to know or do, with a link to the dedicated guide that goes deep. The sections that carry real weight are the ones no single spoke covers: the Self Assessment registration deadline, record-keeping habits, budgeting for tax as you go, and the accountant-vs-DIY decision. For a wider list of free websites and learning resources, see our best Self Assessment resources guide.
What Does Self-Employed Mean for Tax?
Being self-employed for tax means you run your own business, are responsible for declaring your income to HMRC, and pay your own tax and National Insurance through Self Assessment rather than PAYE. You are taxed on your profit (income minus allowable expenses), not on what you draw out, and you must register for Self Assessment if your gross self-employment income exceeds £1,000 in a tax year. The trade-off for the lack of employee rights (no sick pay, no holiday pay) is autonomy, the ability to claim business expenses, and flexibility over how and when you work.
1. Are you actually self-employed?
Before you register for anything, make sure you are genuinely self-employed in HMRC’s eyes. The test isn’t what you call yourself — it’s whether you’re in business on your own account, taking financial risk, deciding how and when you work, and able to send a substitute, as set out in HMRC’s guidance on working for yourself. If a client dictates your hours, provides your equipment and can’t be turned down, you may be a worker or an employee even if they call you a contractor. Getting this wrong is expensive, so for the full employment-status tests (including IR35 and the gig-economy edge cases), see our guide on employed or self-employed tax.
2. Register for Self Assessment (the deadline you’ll miss)
This is the step that catches more new sole traders than any other. You must register for Self Assessment by 5 October after the end of the tax year in which you first became self-employed. So if you started trading in June 2026, your registration deadline is 5 October 2027 — not 31 January, which is the filing deadline people actually know about.
Registration is not automatic. You sign up through HMRC, they send you a UTR (Unique Taxpayer Reference) in the post, and the whole process can take several weeks. If you miss the 5 October deadline, don’t panic — register anyway. The penalty for late registration is usually £0 for first-time filers, but it increases the longer you leave it under HMRC’s failure-to-notify rules. See our didn’t know you had to register guide for what happens if you registered late.
3. How you pay yourself — and how you’re taxed
As a sole trader, you don’t take a salary — you take drawings from the business. There is no tax deduction for drawings; you are taxed on your profit (income minus allowable expenses), not on what you take out. This is the single biggest difference between a sole trader and a limited company, and it affects how you budget, how you save, and when you pay tax. You’ll also face Payments on Account — HMRC’s system of asking for half your next year’s tax in advance, which catches almost every new sole trader off guard. For the full breakdown of drawings, take-home pay calculations, and how Payments on Account work, see our guide on how to pay yourself as a sole trader.
4. Get a business bank account
You are not legally required to have a business bank account as a sole trader, but you should get one. Mixing personal and business transactions in the same account makes record-keeping harder, weakens your position if HMRC asks questions, and most banks’ terms require a business account if the account is used primarily for trading. Several challenger banks offer free business accounts for sole traders with no monthly fee, and many integrate directly with accounting software. For the comparison table, fee breakdowns, and which accounts work best for MTD, see our best business bank accounts for sole traders guide.
5. The tax year and its key deadlines
The UK tax year runs from 6 April to 5 April the following year — not January to December, and not April to March. Your Self Assessment return covers one tax year and is due by 31 January after it ends. So the return for the 2026/27 tax year (6 April 2026 to 5 April 2027) is due by 31 January 2028. There are also Payments on Account deadlines on 31 January and 31 July. If you’re moving to Making Tax Digital, there are quarterly update deadlines on top of these. For the full calendar of dates, what changed in 2026/27, and how the deadlines interact, see our UK tax year explained guide.
6. Keep records from day one
This is the habit that separates sole traders who sail through January from those who spend a weekend in a panic. You need to keep a record of every business transaction — income and expenses — with enough detail to support what you put on your tax return. That means the date, amount, what it was for, and a receipt or equivalent (bank statement, invoice, email confirmation). You don’t need a formal accounting system on day one — a spreadsheet or a simple app is fine — but you do need to start immediately, not reconstruct everything in January.
HMRC requires you to keep records for at least 5 years after the 31 January submission deadline for the relevant tax year. If you lose records, you can estimate, but HMRC will penalise careless estimates. The cost of not keeping records isn’t just the penalty — it’s the expenses you forget to claim, which is usually a bigger number.
For a structured timeline of what to keep and when, see our first-year self-employed checklist.
7. Budget for tax as you go
The most common first-year mistake is treating all the money in the bank account as yours. It isn’t — some of it belongs to HMRC, and if you spend it, you won’t have it when the bill arrives on 31 January.
The simplest method is the tax pot: every time you receive a payment, move roughly 25-30% of the profit into a separate savings account. This covers Income Tax (20% basic rate or 40% higher rate) and National Insurance (Class 2 at £3.50/week and Class 4 at 6% on profits over £12,570 in 2026/27). If you also have a PAYE job, your self-employed income is taxed on top of your salary, which can push you into the higher band sooner than you expect — so check your total income, not just your business income.
Two things make the first-year bill bigger than people expect:
- Payments on Account: HMRC asks for half your next year’s tax in advance, on top of your current year’s bill. So your first 31 January could be 150% of what you expected.
- No tax deducted at source: Unlike PAYE, nobody takes tax out of your self-employed income before it reaches you. You have to do it yourself.
Budget for 150% of your expected tax bill in your first January, and you won’t be caught out.
8. Watch the VAT threshold
You must register for VAT if your turnover (not profit) exceeds £90,000 in any rolling 12-month period, or if you expect it to exceed £93,000 in the next 30 days. You can also register voluntarily below the threshold, which can be worth it if your customers are VAT-registered businesses (they can reclaim the VAT you charge, so it doesn’t cost them more).
VAT registration brings extra admin — quarterly VAT returns, VAT-inclusive pricing decisions, and VAT on your own purchases — but it also lets you reclaim VAT on business expenses you’ve already paid. The threshold is a hard line, not a buffer, and HMRC checks. For the full threshold rules, the Flat Rate Scheme, and how to register, see our VAT registration for sole traders guide.
9. Your first-year checklist
All of the above is easier to manage if you have a structured timeline. Our first-year self-employed checklist walks through what to do and when, from the day you start trading through to your first 31 January deadline. It covers registration, record-keeping, Payments on Account, and the trading allowance — the practical companion to this guide.
10. Accountant or DIY?
This is a judgement call, and the answer changes as your business grows. Most sole traders are fine filing their own return — or using a tax return service — until their net profit reaches roughly £30,000-£40,000. Below that, the tax saving an accountant produces is usually smaller than their fee, and good accounting software (FreeAgent, Pie Tax, Coconut) handles the record-keeping and filing for a fraction of the cost.
Above £30,000-£40,000, or when your situation gets complicated — multiple income sources, VAT registration, a property portfolio, thinking about incorporating — an accountant typically pays for themselves in tax saved and penalties avoided. The decision isn’t just about cost; it’s about how much of your own time you want to spend on tax admin versus doing the work that earns you money.
For the full comparison of tax return services, accountants and DIY software — with cost breakdowns at different income levels — see our tax return service vs accountant vs software guide and our should I hire an accountant decision guide.
The Bottom Line
- Confirm your status first. If you’re not genuinely self-employed, everything else is built on sand.
- Register for Self Assessment by 5 October — not 31 January. This is the deadline nobody knows about.
- You’re taxed on profit, not on what you take out. Drawings are not a tax deduction.
- Get a business bank account even though it’s not legally required. It makes everything easier.
- Keep records from day one. Reconstructing in January costs you more in missed expenses than in time.
- Set aside 25-30% of profit for tax, and budget for 150% in your first January because of Payments on Account.
- Watch the £90,000 VAT threshold. It’s based on turnover, not profit, and it’s a hard line.
- DIY is fine until ~£30,000-£40,000 profit. Above that, an accountant usually pays for themselves.
For the full timeline of what to do and when in your first year, see our first-year self-employed checklist. For the complete guide to reducing your tax bill — expenses, capital allowances, pensions, Gift Aid and more — see our reduce your Self Assessment tax bill hub. For the full list of what you can and can’t claim as a sole trader, see our allowable expenses guide. If you’re approaching Making Tax Digital, our Making Tax Digital guide covers what changes and when.