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Self Assessment tax calculator for 2026/27
Estimate the income tax and Class 4 National Insurance on your self-employed profit for the 2026/27 tax year (6 April 2026 to 5 April 2027).
For 2026/27 you pay no income tax on the first £12,570, 20% up to £50,270, 40% up to £125,140 and 45% above. The self-employed also pay Class 4 National Insurance: 6% on profits between £12,570 and £50,270, and 2% above.
Over £1,000, so HMRC will usually ask for payments on account: two of £4,865.90 towards next year, in January and July. In your first year, January can be the whole bill plus the first of those.
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Tax is on profit: income minus allowable expenses. The calculator uses the 2026/27 rates for England, Wales and Northern Ireland (Scotland has different income tax bands).
| Band | Profit | 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% |
The Personal Allowance goes down by £1 for every £2 of income over £100,000. Class 4 National Insurance is 6% on profit between £12,570 and £50,270, and 2% above that.
Worked example
Income of £60,000 minus £10,000 of expenses is £50,000 profit. Income tax is £7,486.00 and Class 4 National Insurance £2,245.80: a total of £9,731.80, 19.5% of profit.
An estimate, not tax advice. It leaves out other income, student loans, pension relief and CIS already deducted.
Questions
When is the 2026/27 tax return due?
Online returns for the year ending 5 April 2027 are due by 31 January 2028, and so is the tax.
What is a payment on account?
If your bill is over £1,000, HMRC usually asks for two advance payments towards next year, each half of this year's bill, on 31 January and 31 July. In your first year, January can be the bill plus the first advance.
What expenses can I claim?
Costs wholly for the business: materials, tools, van or mileage, fuel, insurance, phone, workwear, software and accountant fees. Keep every receipt.
Do I still pay Class 2 National Insurance?
No. Since April 2024 self-employed people don't have to pay Class 2; you can pay it voluntarily to protect your State Pension record if your profits are low.
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