Tax is the number one source of anxiety for UK freelancers. The rules feel complex, the deadlines feel arbitrary, and the penalties for getting it wrong feel disproportionate. This guide breaks down everything you need to know for the 2025/26 tax year.
Disclaimer
This guide provides general information about UK freelancer tax obligations. It is not a substitute for professional tax advice. Consult a qualified accountant for advice specific to your circumstances.
Registering for Self Assessment
If you earn more than £1,000 from self-employment in a tax year, you must register with HMRC for Self Assessment. You need to register by 5 October following the end of the tax year in which you started freelancing.
Income Tax Bands (2025/26)
| Band | Taxable Income | Rate |
|---|---|---|
| Personal Allowance | Up to £12,570 | 0% |
| Basic Rate | £12,571 to £50,270 | 20% |
| Higher Rate | £50,271 to £125,140 | 40% |
| Additional Rate | Over £125,140 | 45% |
National Insurance Contributions
As a sole trader, you pay two types of NIC:
- Class 2 — £3.45 per week (if profits exceed £12,570)
- Class 4 — 6% on profits between £12,570 and £50,270, plus 2% on profits above £50,270
Key Deadlines
5 April 2026
Tax year ends
31 October 2026
Paper tax return deadline
31 January 2027
Online tax return deadline and payment of tax owed
31 July 2026
Second payment on account deadline
Payments on Account
If your tax bill exceeds £1,000, HMRC will ask you to make "payments on account" — two advance payments towards the following year's tax bill. Each payment is 50% of the previous year's tax bill.
The Tax Bill Shock
In your first year of Self Assessment, you may need to pay your entire tax bill PLUS the first payment on account — effectively 150% of one year's tax in a single payment. Set money aside from every invoice to avoid this shock.
Saving for Tax
A common rule of thumb: set aside 25-30% of every payment you receive into a separate savings account. This covers Income Tax, NICs, and provides a buffer for payments on account.
Allowable Expenses
You can deduct legitimate business expenses from your income before calculating tax. Common deductions include:
Office costs
Equipment, software, stationery, phone bills
Travel
Business travel, mileage at 45p/mile for first 10,000 miles
Professional development
Courses, books, conferences directly related to your work
Insurance
Professional indemnity, public liability
Marketing
Website hosting, advertising, business cards
Home office
Proportion of rent/mortgage, utilities, broadband (or simplified expenses)
VAT
You must register for VAT if your taxable turnover exceeds £90,000 in a 12-month period. You can voluntarily register below this threshold if it benefits you — for example, if most of your clients are VAT-registered businesses.
Common Mistakes to Avoid
- Not keeping records — HMRC requires you to keep records for at least 5 years
- Missing deadlines — late filing penalties start at £100 and escalate
- Not setting money aside — treat tax savings as non-negotiable from every payment
- Claiming personal expenses — only claim expenses that are wholly and exclusively for business
- Ignoring payments on account — budget for these from the start