UK Self Assessment Spreadsheet 2025/26 for Sole Traders, Tax Estimate and Expense Tracker

Get your 2025/26 Self Assessment sorted before the 31 January 2027 deadline, without the shoebox of receipts.

Built for UK sole traders, freelancers and side hustlers. Log your income, expenses and mileage and the workbook does the rest: totals by HMRC category, the £1,000 trading allowance check, and an estimate of your income tax, Class 4 National Insurance and payments on account.

WHAT'S INSIDE
• Income log, with a check for entries outside the tax year
• Expenses log with dropdown categories that match HMRC's self-employment boxes, plus business-use % for shared costs
• Mileage log with 45p / 25p per mile applied automatically, including the 10,000-mile switch
• Summary with figures laid out ready for your self-employment pages
• Trading allowance vs expenses: tells you which gives the lower bill
• Tax estimate: income tax + Class 4 NI at 2025/26 rates, taking your PAYE salary into account
• Savings target: how much to set aside each month before 31 January
• Making Tax Digital checker: will MTD apply to you from 6 April 2027 (£30,000 threshold)?
• Key dates: every deadline with a days-left countdown

WORKS WITH
Microsoft Excel, Google Sheets (File > Import) and Apple Numbers. Instant download. No physical item is sent.

PLEASE NOTE
This is an organiser and estimator, not tax advice, and it doesn't file your return. Uses 2025/26 rates for England, Wales and Northern Ireland (Scottish income tax bands differ). Estimates don't include student loans, pension relief, Gift Aid, capital allowances or losses. Not affiliated with HMRC.

Questions? Message me. I usually reply within a day.