Self-Employed Tax Estimate and Payments on Account Planner 2026/27

Work out what you owe on 31 January and 31 July, and what to put aside each month. A spreadsheet for UK sole traders, for tax year 2026/27.

THIS IS AN ESTIMATE FOR PLANNING, NOT TAX ADVICE. Your real bill is whatever HMRC works out from your Self Assessment return.

Type in your expected 2026/27 profit, any other taxable income and your last Self Assessment bill. The workbook then shows:

• income tax by band for the rest of the UK or Scotland, with the personal allowance cut above £100,000
• Class 4 National Insurance, plus voluntary Class 2 if you choose it, and student loan repayments
• the £1,000 and 80% collected at source tests for payments on account
• your balancing payment and first payment on account for 31 January 2027, and the second payment on account for 31 July 2027
• a look ahead to January and July 2028
• a monthly set-aside figure, and a month-by-month pot for the year
• the same profit under 2025/26 and 2026/27 rates

Each step of the sum is written out, so you can check it against your own return. Rates are on a separate sheet with the gov.uk page each came from, checked on 2026-11-06.

You get two .xlsx files: an example for a self-employed electrician in England, and a blank copy. They work in Excel 2016 or later and in Google Sheets. No macros, no password.

It does not connect to HMRC and sends nothing. It covers one self-employment business and leaves out Class 1 National Insurance on a job, pension contributions, Gift Aid, dividends, savings and rental income.

This does not send anything to HMRC. You type the figures into your Self Assessment return or software.

Figures are estimates for planning. They are not tax advice.