Deadlines and admin
Registering as a self-employed sole trader
You can trade from day one; the duty is to tell HMRC in time, and the date depends on when your tax year ends.
A sole trader who starts in June 2026 has until 5 October 2027 to register for Self Assessment, and on 31 January 2028 pays the first bill: on £18,000 of profit in England, Wales or Northern Ireland that is £1,412, plus a first payment on account of £706. Registration becomes compulsory once your gross self-employed income in a tax year is more than £1,000, counted before any expenses, and the cut-off is 5 October after the end of that tax year (which runs from 6 April to 5 April). Nothing stops you trading before you register, and you can register early. HMRC then sends a ten-digit Unique Taxpayer Reference, the UTR, which you need to file online. Pick the month you started below to see your own register-by date, the first return and the two payment dates that follow.
Started trading? Your first deadlines
Register with HMRC by
5 October 2027
| First tax year | 2026/27 |
| Online return due | 31 January 2028 |
| First tax payment | 31 January 2028 |
| Second payment on account | 31 July 2028 |
Figures checked by Radif Partners · Editorial policy · How we calculate
The trigger: gross income, not profit
The test HMRC applies is simple and catches people out because it ignores costs. A dog walker who invoices £1,400 in a year and spends £600 on leads, insurance and fuel has made a profit of £800, yet the gross figure is over £1,000, so registration is required. Below that line the trading allowance makes the income tax-free and there is nothing to tell HMRC (HMRC guidance on the trading allowance). Above it, you register and then choose on the return between deducting the allowance or your real expenses.
Several small trades count together. A tutor who also sells prints online adds both gross amounts before comparing with the limit. Wages from a job sit outside this test, but if you already file a return for another reason, the business simply goes on that return.
When the date falls
The cut-off belongs to the tax year, not to the day you started. HMRC must hear from you by 5 October after the 5 April that closes your first trading year. For the year that ended on 5 April 2026, that was 5 October 2026; for 2026/27 it is 5 October 2027. Starting in March rather than April makes a whole year of difference:
| Started trading | First tax year | Register by | First return and payment | Second payment on account |
|---|---|---|---|---|
| February 2026 | 2025/26 | 5 October 2026 | 31 January 2027 | 31 July 2027 |
| April 2026 (after the 5th) | 2026/27 | 5 October 2027 | 31 January 2028 | 31 July 2028 |
| September 2026 | 2026/27 | 5 October 2027 | 31 January 2028 | 31 July 2028 |
| March 2027 | 2026/27 | 5 October 2027 | 31 January 2028 | 31 July 2028 |
The same cut-off applies to someone who registered years ago but did not have to send a return for 2024/25: their account needs reactivating rather than a fresh registration, and the online service tells you which applies (GOV.UK, how to register).
Missing the cut-off
A late registration does not stop you filing. HMRC writes with a personal filing deadline set three months from the date of its letter, but the tax itself is still due by 31 January 2027 for the 2025/26 year (GOV.UK, Self Assessment deadlines). The risk is the failure to notify penalty: it applies when you registered after 5 October and have not paid the whole bill by 31 January, and it is based on what remains unpaid (GOV.UK, Self Assessment penalties). Paying in full on time is the practical defence. The late filing and payment penalties are a separate set of charges.
GOV.UK states that you can register before you reach £1,000. A photographer who expects to pass the limit in the autumn can register in the spring and have the UTR in hand long before the first return is due.
What you get back, and what you need
Registration produces a Unique Taxpayer Reference, a ten-digit number that HMRC also calls a tax reference. It normally arrives by post around 15 days later. It is printed on later letters, on notices to file and payment reminders, and appears in your personal tax account and the HMRC app. To file online you need it, plus sign-in details, and HMRC may ask you to prove your identity with photo ID such as a passport or driving licence. Add your bank details to the return so that any refund can be paid straight back.
Before any of that, start keeping records: every sale and every business expense, from the first invoice. Since 2024/25 the cash basis is the default way to count them, recording money when it actually comes in or goes out. You do not send the records to HMRC, but you need them to work out the profit and must be able to show them if asked.
If you also have a job
Being employed does not exempt you. A tutor earning £26,000 on PAYE who makes £9,000 of profit from evening lessons registers like anyone else; the wages have already used the Personal Allowance, so the whole profit is taxed at the basic rate. The return for that tutor shows £1,800 of Income Tax to pay through Self Assessment, and no Class 4, since the profit is under the £12,570 lower profits limit. The job plus self-employment page works through these cases.
Beyond income tax
Registering for Self Assessment covers Income Tax and National Insurance on your profits. VAT is a separate registration with its own test on sales, explained on the VAT threshold page. Depending on the trade you may also need a licence (street trading, food, music), insurance, or a criminal record check for work with children or vulnerable adults, all listed on GOV.UK, set up as a sole trader. Once registered, the next dates to watch are on the Self Assessment calendar.