Step 1: Register for Self Assessment
If you started driving as a self-employed person in the 2024/25 tax year (6 April 2024 – 5 April 2025) and haven't registered yet, you must do so by 5 October 2025. Missing this deadline can result in a £100 penalty.
Register at gov.uk/register-for-self-assessment. You'll need your National Insurance number and contact details. HMRC will send you a Unique Taxpayer Reference (UTR) number by post within 10 working days. Keep this safe — you'll need it for every future return.
⚠ Already Self-Employed?
If you were registered as self-employed in a previous year and simply continued driving, you are already registered. You just need to file your return by the deadline and ensure your UTR is active.
Step 2: Gather Your Income Records
You must declare all your income from self-employment. For taxi and private hire drivers, this includes:
- Cash fares — all cash payments received, even if not recorded on an app
- Card/app payments — your gross earnings as shown on your platform statements (Uber, Bolt, Free Now, etc.)
- Tips — cash and card tips are taxable income and must be declared
- Private bookings — fares booked directly with you outside any platform
HMRC requires you to report your gross income before expenses. Platform commission fees are deducted as an expense, not from your income figure.
Step 3: Calculate Your Allowable Expenses
Deducting all legitimate expenses reduces your taxable profit. The key expenses for taxi drivers are:
- HMRC mileage allowance (45p/mile for first 10,000; 25p thereafter) — OR actual vehicle costs
- Vehicle licensing and PHV badge fees
- DBS check and medical fees for licence renewal
- Mobile phone (business percentage)
- Accountancy fees
- Platform commission fees (Uber, Bolt, etc.)
See our full guide: Complete List of Allowable Expenses for Taxi Drivers.
Step 4: Complete the Self Assessment Forms
When you file online at gov.uk/file-your-self-assessment-tax-return, you need to complete:
- SA100 — the main Self Assessment tax return form (completed for everyone)
- SA103S or SA103F — the self-employment supplementary pages. Use SA103S ("Short") if your annual turnover is below £85,000; use SA103F ("Full") if above £85,000 or if you have complex affairs
The SA103 form asks for your business income, allowable expenses, and net profit. HMRC's online filing system guides you through this step by step.
Step 5: Key Deadlines
| Deadline | Date (for 2024/25 tax year) |
|---|---|
| Register for Self Assessment | 5 October 2025 |
| File paper tax return | 31 October 2025 |
| File online tax return | 31 January 2026 |
| Pay tax owed | 31 January 2026 |
| Second payment on account (2025/26) | 31 July 2026 |
Step 6: Payment on Account
If your Self Assessment tax bill exceeds £1,000, HMRC requires you to make Payments on Account — advance payments towards the following year's tax bill. Each payment is 50% of your previous year's tax bill, due in January and July.
This catches many first-year drivers by surprise: in your first Self Assessment year, you may owe your full year's tax plus 50% of that amount as an advance for the next year — all due on 31 January. Budget carefully.
Do You Need an Accountant?
HMRC's online Self Assessment system is designed to be completed without professional help, and many drivers do so successfully. However, an accountant can help you if:
- You have multiple income sources (employment plus self-employment)
- You're unsure how to handle capital allowances on your vehicle
- Your turnover is near the VAT registration threshold (£90,000 in 2025/26)
- You've received any HMRC enquiry letters
Accountancy fees are themselves a deductible expense, reducing the after-tax cost of professional advice.
Estimate Your Tax Bill Before You File
Use our free calculator to estimate your Income Tax, Class 4 NI, and mileage relief before sitting down to file your Self Assessment return.
Open Free Tax Calculator →Frequently Asked Questions
I only drove taxis part-time. Do I still need to file?
Yes. If your self-employment income exceeds £1,000 in a tax year (the trading allowance threshold), you must register and file a Self Assessment return. Even below £1,000, if you have other taxable income, filing may still be required.
What if I also have a PAYE job?
You must declare both your employment income (from your P60) and your self-employment income on your Self Assessment return. Tax already paid through PAYE will be credited against your total tax bill.
Can I amend my tax return after filing?
Yes. You can amend an online Self Assessment return up to 12 months after the original filing deadline. After that, you must contact HMRC directly to make corrections.