UK Tax Calculator Tax year 2026/27

Allowable expenses (2026/27)

The HMRC-accepted categories you can deduct from profit, plus the simplified-expenses shortcut.

Overview

If you're self-employed, your tax bill is calculated on profit (income minus allowable expenses), not gross income. Claiming everything HMRC permits is the single biggest legal lever on your tax bill - every £1,000 of expenses saves £200–£420 depending on your marginal rate.

Quick reference: a fuller, worked-example version of this guide is in development. The figures below are accurate for 2026/27 as of the last build.

Key facts

Trading allowanceFirst £1,000 of self-employed income is tax-free; you can claim either the £1,000 allowance OR actual expenses, not both.
Simplified expensesFlat-rate alternative for vehicles, working from home, and living in business premises. Optional.
Mileage rates (cars)45p/mile for the first 10,000 business miles, 25p/mile thereafter

Categories HMRC accepts

The simplified-expenses option

HMRC publishes flat rates that let you skip the receipt-arithmetic for three categories where the actuals are fiddly:

You can mix simplified and actual expenses across categories. Use whichever gives the bigger deduction in each.

What's not deductible

Sources

Related guides

Or run the numbers for your own profit level: £50,000 self-employed, £75,000 self-employed, or browse all bracket pages.