HMRC Self Assessment 2026: Deadlines, Penalties & How to File
UK gig workers with income over £1,000 must submit an HMRC Self Assessment return each year. The online filing deadline is 31 January following the end of the tax year. Missing it triggers an automatic £100 penalty, rising to £1,600+ after six months. You must register by 5 October if it is your first return.
Key Takeaways
- Online filing deadline: 31 January 2027 for the 2025/26 tax year
- Register for Self Assessment by 5 October 2026 if you are new
- Trading allowance: first £1,000 of self-employment income is tax-free
- Late filing penalty starts at £100 immediately after the deadline
- Personal Allowance 2026: £12,570 — no income tax below this threshold
- Keep financial records for at least 5 years after submission
Table of Contents
- Who Needs to Submit Self Assessment?
- Key Deadlines for 2026
- How to Register with HMRC
- How to File Your Return Step by Step
- What to Include in Your Return
- How Much Tax Will You Owe?
- Penalties for Late Filing or Payment
- Allowable Deductions for Gig Workers
- How to Pay Your Tax Bill
- Frequently Asked Questions
Who Needs to Submit a Self Assessment Return?
HMRC requires a Self Assessment return from anyone who receives income that has not been taxed at source. For gig economy workers, this covers nearly every platform payment you receive.
You must submit a return if any of the following apply in the 2025/26 tax year:
- You are self-employed and earned more than £1,000 before expenses (the trading allowance)
- You are a company director receiving a salary or dividends
- Your total income exceeds £100,000
- You received untaxed income such as rental income or investment returns
- You earned income from abroad
- You need to claim tax relief on pension contributions or Gift Aid donations
- You received Child Benefit and your income exceeds £60,000
"You must send a tax return if, in the last tax year (6 April to 5 April), you were self-employed as a sole trader and earned more than £1,000."
— GOV.UK — Self Assessment tax returns
If you drive for Uber, deliver for Deliveroo, rent via Airbnb, or complete tasks on any gig platform, HMRC considers you self-employed. You must register and file annually regardless of whether you also hold a PAYE job.
What Are the Key Self Assessment Deadlines for 2026?
Missing any of these dates results in financial penalties. Mark them in your calendar now.
| Deadline | Date | What It Covers |
|---|---|---|
| Register for Self Assessment | 5 October 2026 | New self-employed workers registering for the first time |
| Paper return filing | 31 October 2026 | Submit paper SA100 form to HMRC by post |
| Online return filing | 31 January 2027 | Submit your 2025/26 return via HMRC online or software |
| Pay tax owed | 31 January 2027 | Balance payment + first payment on account for 2026/27 |
| Second payment on account | 31 July 2027 | Second instalment toward your 2026/27 tax bill |
The tax year in the UK runs from 6 April to 5 April. The 2025/26 tax year therefore ends on 5 April 2026. You then have until 31 January 2027 to file your online return and settle any tax owed.
How Do I Register for Self Assessment with HMRC?
If this is your first Self Assessment return, you must register before you can file. HMRC needs time to issue your Unique Taxpayer Reference (UTR) by post, which takes up to 10 working days.
- Visit GOV.UK — Self Assessment login and select "Create a Government Gateway account" if you do not already have one
- Select "I need to tell HMRC that I am self-employed" and complete the online registration form
- Provide your National Insurance number, date of birth, and contact details
- HMRC will post your UTR (10-digit number) within 10 working days
- Use your UTR to log in to your HMRC online account and activate Self Assessment
- You are now able to file your return online
Register by 5 October 2026 for the 2025/26 tax year. Registering late does not extend your filing deadline — penalties still apply from 31 January 2027.
How Do You File a Self Assessment Return Step by Step?
Filing your return takes approximately 30 to 90 minutes if your records are organised. Use the HMRC online service or HMRC-approved software.
- Gather your records. Collect all income from gig platforms, bank statements, expense receipts, and mileage logs for the full tax year (6 April 2025 to 5 April 2026)
- Log in to your HMRC account. Go to GOV.UK and sign in with your Government Gateway credentials
- Complete the SA100 form. Enter your self-employment income under the Self-Employment supplementary pages (SA103S for simple cases or SA103F for full accounts)
- Enter your allowable expenses. Include mileage allowance, equipment, phone, and any other legitimate business costs
- Review your tax calculation. HMRC calculates your Income Tax and Class 4 National Insurance automatically based on your entries
- Check and submit. Review all figures, then click submit before 31 January 2027
- Pay what you owe. Use bank transfer, debit card, or set up a Time to Pay arrangement if needed
What Should You Include in Your Self Assessment Return?
Accuracy matters. HMRC can investigate returns up to four years after filing, or 20 years in cases of suspected fraud.
- Total gig income: All platform earnings before any deductions, including tips and bonuses
- Trading allowance: Deduct up to £1,000 automatically if your expenses are lower than this amount
- Allowable expenses: Mileage, equipment, phone bills, and professional fees
- PAYE income: Include any employment income from your P60 or P45
- Bank interest: Interest above the Personal Savings Allowance (£500 for basic rate taxpayers in 2026)
- Other income: Rental income, dividends, or capital gains if applicable
Platform Income: What Counts as Taxable?
Every payment from Uber, Deliveroo, Amazon Flex, Bolt, or any other platform counts as self-employment income. This includes:
- Delivery and ride fees paid by the platform
- Customer tips processed through the app
- Bonuses, incentives, and promotional pay
- Referral payments from the platform
Private cash tips not processed through the platform are also taxable and must be declared.
How Much Tax Will a Gig Worker Owe in 2026?
Your tax bill depends on your total taxable profit after allowable expenses. The Personal Allowance for 2026 is £12,570.
| Annual Profit | Income Tax | Class 4 NI (6%) | Total Tax |
|---|---|---|---|
| £12,570 or less | £0 | £0 | £0 |
| £25,000 | £2,486 | £747 | £3,233 |
| £28,000 (Uber Eats) | £3,086 | £927 | £4,013 |
| £30,000 (Amazon Flex) | £3,486 | £1,047 | £4,533 |
| £35,000 (Uber) | £4,486 | £1,347 | £5,833 |
| £50,270 (higher rate threshold) | £7,540 | £2,262 | £9,802 |
Class 4 National Insurance is charged at 6% on profits between £12,570 and £50,270. Class 2 National Insurance was abolished from April 2024 and is no longer payable.
Use the UKGigTax calculator to get a precise figure based on your actual earnings and expenses.
What Are the Penalties for Late Filing or Late Payment?
HMRC imposes automatic penalties for missing the Self Assessment deadline. These apply even if you owe no tax.
Late Filing Penalties
- 1 day late: Automatic £100 fixed penalty
- 3 months late: £10 per day (up to 90 days — maximum £900)
- 6 months late: Additional 5% of tax owed or £300 (whichever is greater)
- 12 months late: Further 5% of tax owed or £300 (whichever is greater)
Late Payment Penalties
- 30 days late: 5% of unpaid tax
- 6 months late: Further 5% of unpaid tax
- 12 months late: Further 5% of unpaid tax
- Interest: Charged daily on all overdue amounts at the HMRC late payment rate
If you cannot pay your tax bill in full, contact HMRC before the deadline to arrange a Time to Pay agreement. This spreads payments over up to 12 months and avoids late payment penalties.
What Deductions Can Gig Workers Claim on Self Assessment?
Allowable expenses reduce your taxable profit, which directly reduces your tax bill. Claim everything you are entitled to.
- Mileage allowance: 45p per mile for the first 10,000 business miles, 25p per mile thereafter
- Bicycle mileage: 20p per mile (applicable to Deliveroo and Bolt Food riders)
- Phone and data: The business-use proportion of your monthly bill
- Equipment and gear: Insulated bags, helmets, safety equipment — 100% if used solely for work
- Professional fees: Accountant fees, tax software subscriptions
- Insurance: Public liability or courier-specific insurance premiums
- Platform fees: Any fees charged by the gig platform deducted from your earnings
You cannot claim clothing unless it is a uniform or protective gear. Everyday cycling or driving clothes do not qualify. See our guide to National Insurance for the self-employed in 2026 for more on reducing your overall tax burden.
Mileage vs Actual Costs: Which Is Better?
Most gig workers benefit from claiming the HMRC mileage allowance rather than actual vehicle costs. At 45p per mile, a driver covering 8,000 business miles per year can claim £3,600 in deductions — with no need to track fuel, insurance, or depreciation separately. Actual costs calculations require detailed record-keeping and rarely produce a higher deduction for part-time gig workers.
How Do You Pay Your Self Assessment Tax Bill?
HMRC accepts several payment methods. Allow enough time for your payment to reach HMRC before the deadline — some methods take up to five working days.
- Online or telephone banking: Use HMRC's sort code and account number with your UTR as the reference (same day)
- CHAPS: Same-day transfer for large amounts (charges may apply)
- Debit card: Pay online via your HMRC account (1–2 working days)
- Direct Debit: Set up via your HMRC online account (allow 5 working days for first payment)
- Cheque: Post to HMRC with a payslip from your online account (allow 5 working days)
Credit card payments are not accepted for Self Assessment. Always use your 10-digit UTR as the payment reference so HMRC can match your payment correctly.
Frequently Asked Questions
What is the deadline for Self Assessment in 2026?
The online Self Assessment deadline for the 2025/26 tax year is 31 January 2027. The paper return deadline is 31 October 2026. You must also pay any tax owed by 31 January 2027.
Who needs to submit a Self Assessment tax return?
You must submit a return if you are self-employed with income over £1,000, a company director, a higher-rate taxpayer with untaxed income, or earned more than £100,000 in the tax year.
What is the penalty for missing the Self Assessment deadline?
Missing the 31 January deadline results in an automatic £100 penalty. After 3 months, daily £10 penalties apply (up to £900). After 6 months, a further 5% of tax owed or £300 is charged.
Do gig workers need to submit a Self Assessment?
Yes. If you earn more than £1,000 from gig work — including Deliveroo, Uber, Amazon Flex, or similar platforms — you must register for Self Assessment and submit an annual tax return.
How do I register for Self Assessment?
Register online via GOV.UK by 5 October following the end of the tax year. You will receive a Unique Taxpayer Reference (UTR) within 10 working days by post.
Can I claim mileage allowance on my Self Assessment return?
Yes. Self-employed workers can claim 45p per mile for the first 10,000 business miles and 25p per mile thereafter. Bicycle riders can claim 20p per mile.
What records do I need to keep for Self Assessment?
You must keep records for at least 5 years after the 31 January submission deadline. These include income records, expense receipts, bank statements, and mileage logs.
Tax compliance specialist since 2017. Helped 5,000+ freelancers and self-employed workers navigate HMRC Self Assessment and UK gig economy tax rules.