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Self Assessment Deadline Planner 2025/26 UK
Self Assessment deadline planner for the 2025/26 UK tax return: every date that applies to you, the exact amount due on 31 January 2027 and what being late would cost.
Preview
What's inside
- Self_Assessment_Deadline_Planner_2025-26_Example.xlsx
- Self_Assessment_Deadline_Planner_Blank.xlsx
- Self_Assessment_Deadline_Wall_Planner_2025-26.docx
What is inside:
- Excel workbook, filled-in example (Joe Bloggs) + blank copy
- My Deadlines: answer 4 Yes/No questions and the list shows only your dates, with weekday, days left and a Done column
- Payments: balancing payment, payments on account, the £1,000 and 80% tests, total for 31 January and 31 July, monthly amount to put aside
- Late Cost: £100 fixed penalty, £10 daily penalties, 5% / £300 steps, 5% late payment steps and interest, each with the date it starts
- Paperwork checklist: 20 documents (P60, P11D, SA103 and SA105 records, interest, gains)
- Printable Word wall planner (2 pages A4): tick-box dates, MTD quarterly updates, a 31 January worksheet and a notes log
Good to know: 31 January 2027 is a Sunday, so Bacs or cheque payments must arrive by Friday 29 January. The planner shows this.
Who it is for: sole traders, landlords and employees with side income anywhere in the UK, Scotland included – deadlines and penalties are UK-wide.
Next year: change one cell from 2026 to 2027 and every date moves to the 2026/27 return (31 January 2028).
How to edit: Microsoft Excel, Google Sheets or LibreOffice for the workbook, Word or Google Docs for the wall planner. No macros, nothing locked.
Format: A4, .xlsx + .docx, UK dates and £. Not tax advice. Rules checked against HMRC guidance on 22 October 2026.
- Fill-in guide in every file: a “Fill in with AI” chapter with ready-made sentences for an AI chat assistant, matched to the template’s fields
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A template you fill in yourself — not legal or tax advice.