FREE Side Hustle Self Assessment Checklist 2025-26 (Printable PDF) — Every Step and Deadline to 31 January 2027

A free one-page printable checklist for UK side hustlers filing a 2025-26 Self Assessment return. It covers 17 tick-box steps, from registering and getting your UTR to filing and paying by 31 January 2027, plus every key date.

Doing a tax return for your side hustle for the first time? Or just want to make sure you haven't missed anything? This free one-page checklist covers the lot in plain English.

What's on the page

• Every key date for the 2025-26 return: registration, the paper deadline, paying through your tax code, 31 January 2027 and the 31 July payment on account.
• 17 tick-box steps in four parts: before you start, gathering your income, gathering your expenses, and deciding, filing and paying.
• The bits people often get wrong:
• selling personal items vs trading
• the 45p mileage rate for 2025-26 (55p only starts from 6 April 2026)
• the £1,000 trading allowance vs actual expenses
• payments on account

Format: a one-page A4 PDF that you can print, or tick on screen in any PDF app.

Want the numbers done for you? The Self Assessment Prep Workbook 2025-26 (£2.99) turns this checklist into an Excel / Google Sheets workbook. It has a progress bar, deadlines that count down, and your figures laid out box by box for the self-employment pages.

Not tax advice, and not an HMRC form. Facts were checked on GOV.UK on 25 October 2026.Instant digital download. Refunds and cancellations: Refunds and cancellations page. This doesn't affect your statutory rights.