Self Assessment Tax Calculator UK 2025/26, Sole Trader & Landlord Tax Return Spreadsheet, Excel Google Sheets, Payments on Account

Seller's description

Know what you'll owe on 31 January - before you file.

This spreadsheet organises a year of self-employed AND rental income, works out the figures your 2025/26 Self Assessment tax return asks for, and estimates your tax bill. That includes the payment on account that makes so many first January bills bigger than people expect.

WHO IT'S FOR
- UK sole traders, freelancers and landlords filing a 2025/26 return (tax year 6 April 2025 to 5 April 2026, online deadline 31 January 2027)
- People with a job plus a side business or rental: enter your salary and the tax already taken off once
- Joint property owners: enter your share once and it's applied to every entry
- Scottish taxpayers: switch on Scottish income tax rates in one click

WHAT'S INSIDE
✔ Dashboard - what to pay in January and July, days to the deadline, record checks
✔ Tax Estimate - income tax (including the Personal Allowance taper over £100,000), Class 4 National Insurance, the 20% mortgage interest relief, tax paid through PAYE, and payments on account (including the £1,000 and 80% rules)
✔ Return Figures - every total in the order of the online return's self-employment and UK property pages
✔ Income & Expenses - drop-down categories that match the tax return
✔ Mileage log - 45p / 25p per mile worked out automatically
✔ Property ledger - up to 10 properties, joint ownership shares, mortgage interest kept separate
✔ Allowance checker - shows whether the £1,000 trading or property allowance beats your expenses
✔ Tax Rates sheet - every 2025/26 rate and band in one place
✔ DEMO file - a full example year so you can see it all working

HOW IT WORKS
1. Fill in Settings: your name, plus job income and PAYE if you have them (5 minutes)
2. Add your income and costs from your bank statements
3. Check the Tax Estimate, then copy each total from Return Figures into your online return

WORKS WITH
Microsoft Excel (Windows, Mac, web, mobile) and Google Sheets (upload, then File > Save as Google Sheets).

PLEASE NOTE
- This is an estimating and record-keeping tool, not tax advice. HMRC's online return calculates your final bill.
- The estimate does not include savings interest and dividends, capital gains, student loan repayments, the High Income Child Benefit Charge, pension and Gift Aid relief, Marriage Allowance or losses. If any of these apply to you, your real bill will differ.
- Not designed for partnerships, limited companies or VAT.
- It doesn't send anything to HMRC; you type the figures into your online return yourself.
- Instant digital download - no physical item will be sent.

Making Tax Digital for Income Tax started in April 2026 for income over £50,000 and reaches £30,000 in April 2027. When you need quarterly updates, see the MTD Record Keeper in my shop.