This free Self Assessment tax calculator estimates your 2026-27 tax bill in Excel. It covers England, Wales and Northern Ireland only, for the 2026-27 tax year. Enter your income, pension and Gift Aid and tax already deducted, and it works out income tax band by band, Class 4 National Insurance, your balancing payment for 31 January 2028 and any payments on account.
What income does it handle?
The calculator takes employment income, self-employment profit, UK property profit, other taxable income such as a pension, savings interest and dividends. It then applies the reliefs in the right order:
- the Personal Allowance, reduced by £1 for every £2 of adjusted net income over £100,000, set against non-savings income first, with any left over split between savings and dividends in whichever way gives the lowest tax (the sheet costs each split where a band or allowance edge is reached and shows the one it used)
- the basic and higher rate limits, extended by gross pension contributions and Gift Aid
- the starting rate for savings, the Personal Savings Allowance and the Dividend Allowance
- Class 4 National Insurance on self-employment profit, and optional voluntary Class 2 for the number of weeks you enter, unless you were over State Pension age on 6 April 2026
2026-27 rates used
| Item | 2026-27 |
|---|---|
| Personal Allowance | £12,570 |
| Basic rate band | £37,700 at 20% |
| Higher rate | 40%, up to £125,140 |
| Additional rate | 45% |
| Starting rate for savings | Up to £5,000 at 0% |
| Personal Savings Allowance | £1,000 basic rate, £500 higher rate, £0 additional rate |
| Dividend Allowance | £500 |
| Dividend rates | 10.75%, 35.75%, 39.35% |
| Class 4 National Insurance | 6% from £12,570 to £50,270, 2% above |
| Class 2 (voluntary) | £3.65 a week if profits are under £7,105 |
Every figure sits on the Rates 2026-27 tab with its gov.uk source, so no rate is hidden inside a formula.
What you pay and when
The balancing payment is your 2026-27 tax and Class 4 National Insurance, less tax already taken off and any payments on account made. It is due by 31 January 2028, together with the first payment on account for 2027-28 if one is needed. The second payment on account is due by 31 July 2028.
This is an estimate for guidance. Check your figures with HMRC or a qualified accountant before relying on them.
Making Tax Digital and your Self Assessment
From 6 April 2026, sole traders and landlords with qualifying income over £50,000 must keep digital records and send quarterly updates under Making Tax Digital for Income Tax. The threshold falls to £30,000 from April 2027 and is due to fall to £20,000 from April 2028. The MTD guide for sole traders explains what changes.
