Tax-pot savings calculator
For sole traders who want to know how much to put aside for tax
Know how much to put aside for tax as you go. Tell it the profit you expect this year (or let it use what you've earned so far) and it estimates the Income Tax and Class 4 National Insurance on that profit. It turns the estimate into pence in every pound to put aside, suggests an amount each month from what you actually made, and tracks your tax pot so you can see if it's keeping up.
Inside the workbook
- EstimateYour expected profit, the tax on it and how much to put aside
- MonthsEach month's profit, what to put aside and your pot
- SourcesEvery rate and rule used, for both tax years, with its GOV.UK link
- Start, How to useA cover with the contents, and plain instructions
Where the figures come from
- Tax year starts
- Tax year ends
- Personal Allowance (standard)
- Allowance cut £1 per £2 of income over
- Basic rate band ends at (income)
- Additional rate on taxable income over
- Basic rate (England, Wales and NI)
- Higher rate of Income Tax
- Additional rate of Income Tax
- Class 4 on profits over
- Class 4 main rate up to profits of
- Class 4 main rate
- Class 4 rate above that
- No payments on account if bill under
- Each payment on account: share of the bill
- Return and January payment due
- July payment on account due
A spreadsheet for organising your own figures. It isn't tax advice, isn't HMRC software and can't send anything to HMRC. Check every figure. Rates and thresholds are for the 2025–26 and 2026–27 tax years (you choose which on the Start sheet) and link to GOV.UK, checked on 18 Oct 2026. If you're not sure what applies to you, ask HMRC or an accountant. Sources and dates are on the Sources tab. Contains public sector information licensed under the Open Government Licence v3.0. Not affiliated with or endorsed by HMRC.