Self Assessment Guide for Self-Employed People
Everything you need to know about filing your 2026-2027 tax return as a self-employed person in the UK
What Is Self Assessment?
Self Assessment is the system HMRC uses to collect Income Tax from people who earn money that is not taxed at source. If you are a self-employed person, private hire worker, or work through platforms like Uber, Bolt, or Free Now, you are required to report your income and expenses to HMRC each year and pay the tax you owe.
Unlike employees who have tax deducted automatically through PAYE, self-employed people must calculate their own tax liability. This means keeping accurate records of all income earned and every business expense throughout the tax year.
Good to know
Even if you made a loss or earned below the personal allowance (currently £12,570), you may still need to file a return if you are registered for Self Assessment. Failing to file on time results in automatic penalties starting at £100.
Who Needs to File a Self Assessment Tax Return?
You must file a Self Assessment return if any of the following apply to you:
You are self-employed as a sole trader (including private hire workers)
Your self-employed income was more than £1,000 in the tax year
You earn income from ride-hailing platforms (Uber, Bolt, Free Now)
You have other untaxed income such as rental income or investments
Key Dates for the 2026-2027 Tax Year
Missing a deadline means automatic penalties. Mark these dates in your calendar:
Tax year begins
Start of the 2026-2027 tax year. Begin tracking all income and expenses from this date.
Register for Self Assessment
Deadline to register with HMRC if this is your first year filing. You need a Unique Taxpayer Reference (UTR).
Tax year ends
End of the 2026-2027 tax year. Make sure all records are complete.
Paper return deadline
If filing by paper, your return must reach HMRC by this date.
Online return + payment deadline
File your online return and pay any tax owed. Late filing incurs a £100 penalty immediately.
What Records Must Self-Employed People Keep?
HMRC requires you to keep accurate records for at least five years after the 31 January submission deadline. Good record-keeping is not just a legal requirement; it also ensures you claim every deduction you are entitled to, reducing your overall tax bill.
Income Records
- Cash fares received daily
- Card payment summaries
- Platform earnings statements (Uber, Bolt, etc.)
- Tips and gratuities
Expense Records
- Fuel receipts and invoices
- Vehicle repair and servicing bills
- Insurance, road tax, and licence costs
- Mileage log with dates, distances, and purposes
Fyled keeps your records automatically
When you log income and expenses in Fyled, we store everything securely and generate HMRC-ready summaries. No more shoeboxes of receipts. Create your free account to get started.
How to Register for Self Assessment
If you have never filed a Self Assessment return before, you need to register with HMRC first. Here is the step-by-step process:
- 1
Create a Government Gateway Account
Visit gov.uk and create your Government Gateway user ID if you do not already have one.
- 2
Register as Self-Employed
Use form CWF1 to register as self-employed. You can do this online through the HMRC website.
- 3
Receive Your UTR Number
HMRC will post your Unique Taxpayer Reference (UTR) within 10 working days. You need this to file your return.
- 4
Set Up Your Online Account
Once you have your UTR, enrol for Self Assessment online so you can file digitally.
Common Self Assessment Mistakes Self-Employed People Make
Missing the 31 January deadline
Late filing attracts an immediate £100 penalty, with further charges after 3, 6, and 12 months. Set a reminder well in advance.
Not claiming all allowable expenses
Many people only claim fuel and forget about insurance, cleaning, phone costs, parking, and training. Check our full list of deductions.
Mixing personal and business expenses
HMRC only allows you to claim the business portion of expenses. If you use your car for personal trips too, only business mileage qualifies.
Poor record keeping
Without proper records, you cannot substantiate your claims during an HMRC enquiry. Digital records are accepted and much easier to manage.
Forgetting about Class 4 National Insurance
On top of Income Tax, you will owe Class 4 NIC at 6% on profits between £12,570 and £50,270, and 2% above that threshold.
Want to know exactly what you can deduct? Read our full guide to allowable tax deductions.
How Fyled Makes Self Assessment Easy
Fyled was built specifically for UK self-employed people. We understand your unique tax situation and have designed every feature around it.
Log Income in Seconds
Record cash fares, card payments, platform earnings, and tips with a few taps.
Track Every Deduction
14 expense categories designed for self-employed people. Never miss a valid claim again.
Tax Calculated Automatically
See your tax liability in real time using the latest 2026-2027 rates and thresholds.
Ready to Take Control of Your Tax Return?
Join thousands of UK self-employed people who use Fyled to track income, maximise deductions, and file their Self Assessment with confidence. It takes less than two minutes to get started.