Self Assessment records checklist for sole traders and subbies
Most tax return stress comes from hunting for paperwork. Work through this checklist for 6 April 2025 to 5 April 2026 and you'll have everything for the 31 January 2027 deadline.
On this page
Checked against GOV.UK on 23 October 2026. General information for sole traders in England, Wales and Northern Ireland, not tax advice. Scottish Income Tax rates are different.
Access and details
- Your UTR: see finding your UTR.
- Your National Insurance number and HMRC online sign-in.
- Bank details for any refund.
Income
- All invoices for the year, or payments received if you use the cash basis (the default since 2024/25).
- Totals before CIS deductions.
- Other income: a job (P60), savings interest, rent.
CIS
- Every monthly statement from each contractor for the year.
- A CIS total checked against your invoices. See CIS statements.
Expenses
- Receipts for tools, materials, PPE, phone, insurance and training. See expenses you can claim.
- Van costs, or a mileage log at 45p a mile for 2025/26. See claiming mileage.
- Hours worked at home each month, for the use of home allowance.
Payments already made
- Payments on account made in January and July 2026.
- Your student loan plan type, if any.
How long to keep records
GOV.UK says to keep records for at least 5 years after the 31 January deadline. For 2025/26, that's until at least 31 January 2032. See how long to keep invoices.
Cash basis or traditional
Under the cash basis you record income when you're paid. An invoice sent in March 2026 but paid in April 2026 falls in 2026/27. You can opt out and use traditional accounting.
Then put your totals into the January tax bill calculator.
This guide is part of our Self Assessment guides for the self-employed.
Free: The UK Contractor's Cheat Sheet 2026/27
CIS rates, overtime maths, tax dates, mileage, VAT and late payment, on 2 pages. Keep it on your phone or print it for the van.
Frequently asked questions
What records do I need for Self Assessment?
Income, expenses with receipts, CIS statements, mileage, payments on account made, and your UTR and HMRC sign-in.
How long must I keep records?
At least 5 years after the 31 January deadline for that tax year.
Do I use invoice date or payment date?
Under the cash basis, the default since 2024/25, the date you were paid.
Sources
- Business records if you're self-employed – GOV.UK
- Expenses if you're self-employed – GOV.UK
- Simplified expenses: vehicles – GOV.UK
- Simplified expenses: working from home – GOV.UK
This guide is general information, not legal, tax or financial advice. Rules and rates change, so check the linked GOV.UK pages for the current position.