Tax set-aside calculator
Self-employed and wondering how much to put aside for Self Assessment? Enter your estimated profit to see income tax, Class 4 National Insurance, a total, and a suggested monthly pot. Uses 2026-27 rates for England, Northern Ireland and Wales.
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How this is worked out
- Personal Allowance: £12,570, reduced by £1 for every £2 of income above £100,000 (zero at £125,140).
- Income tax (England / NI / Wales): 20% on taxable income up to £37,700, 40% up to £125,140 taxable, 45% above that.
- Class 4 NI: 6% on profits between £12,570 and £50,270, then 2% above £50,270.
- Class 2: treated as paid if profits are at or above £7,105 — no cash cost in this calculator.
- Payments on account: if last year was similar, expect about half this total on 31 January and again on 31 July, unless the relevant amount is under £1,000 or more than 80% of the tax was deducted at source.
Sources: GOV.UK income tax rates, self-employed NI rates, payments on account. Scotland has different income tax bands.
Plan the whole year in a spreadsheet
The UK Self Assessment Tax Set-Aside & Payments-on-Account Planner adds an editable rate table, a monthly savings tracker, last-year PoA inputs and a payment calendar. It's available now in the Straight Sums shop for £7.
Get the planner (£7)Starting out as a sole trader? The UK Self-Employed Starter Pack bundles this with the income & expense tracker and the mileage log for £17 (save £6).
Prefer paper? Our printed Self Employed Accounts Book (6 x 9 in, April to March, monthly income and expense pages and a yearly Self Assessment worksheet) is £7.99 on Amazon. Also available from Lulu (£9.99).
Employed too? See what your salary leaves you with in the take-home pay calculator. Comparing the £1,000 trading allowance with expenses? Try the free trading allowance calculator. Logging miles? Use the HMRC mileage allowance calculator. New to payments on account? Read the tax set-aside guide. Never miss 31 January or 31 July: add the free UK tax deadlines calendar. Paying yourself dividends from a limited company? Use the dividend tax calculator. Letting out a property? Try the rental income tax calculator. Over £60,000 with Child Benefit? Check the High Income Child Benefit Charge calculator.