Quick Summary
- Always have your UTR, National Insurance number and HMRC login details ready.
- Employees need their P60, any P45 and P11D.
- Self-employed people and landlords need income and expense records for 6 April to 5 April.
- Don't forget savings interest, dividends, pension contributions and Gift Aid.
- Starting early gives time to find missing paperwork before 31 January.
Most of the stress of a tax return comes from hunting for paperwork. Use this checklist to gather everything for the 2025/26 tax year (6 April 2025 to 5 April 2026) — the return is due online by 31 January 2027. Tick off the sections that apply to you.
1. Your details
- Unique Taxpayer Reference (UTR)
- National Insurance number
- HMRC online account login
- Bank details for any refund
- Any letters from HMRC during the year, such as tax code notices
2. Employment income
- P60 from each employer you worked for on 5 April
- P45 from any job you left during the year
- P11D or payrolled benefits details (company car, health insurance)
- Receipts for work expenses your employer didn't repay
- Details of tips or other income not taxed through payroll
3. Self-employment
- Sales invoices or a record of all takings (cash, card and online)
- Business bank statements for the full year
- Receipts for expenses — see our allowable expenses list
- Mileage log
- Details of equipment or vehicles bought or sold
- CIS payment and deduction statements, if you're a subcontractor
4. Property income
- Rent received for each property (letting agent statements)
- Mortgage interest statements
- Receipts for repairs, insurance, agent fees, landlord registration and other costs
- Ownership share if the property is jointly owned
5. Savings and investments
- Bank and building society interest statements (not ISAs)
- Dividend statements from shares and your own company
- Details of any shares, crypto or property sold — dates, costs and proceeds
- Foreign income or gains
6. Reliefs and other items
- Personal pension contributions (not workplace pensions taken from your pay)
- Gift Aid donations
- Student loan plan type
- Child Benefit received, if either partner's income is over £60,000
- Marriage Allowance transfer, if applicable
- Payments on account you've already made
Tips for a smooth return
- Start in the autumn — missing documents take time to replace.
- Check figures against bank statements rather than memory.
- Keep everything for at least 5 years after the filing deadline (22 months for those not in business or letting property).
Sending this to an accountant? A photo or scan of each item is usually all we need.
Frequently Asked Questions
What documents do I need for Self-Assessment?
Your UTR and National Insurance number, plus records for each income source: P60, P45 and P11D for employment, income and expense records for self-employment or property, and statements for savings, dividends, pension contributions and Gift Aid.
Do I need my P60 for Self-Assessment?
Yes, if you were employed at the end of the tax year. It shows your pay and the tax deducted, which you enter on your return.
How long should I keep tax records?
At least 5 years after the 31 January deadline if you're self-employed or a landlord, and at least 22 months after the end of the tax year otherwise.
Do I need to include ISA interest on my tax return?
No. Interest and gains inside an ISA are tax-free and don't go on your return.
When is the 2025/26 Self-Assessment deadline?
Online returns and payment for the 2025/26 tax year are due by 31 January 2027. Paper returns are due by 31 October 2026.
Hand Us the Paperwork
Send us your documents and we'll prepare and file your tax return, check every relief and tell you exactly what you owe.
Sardar Muhammad, AAT
Sardar is the founder of LimeTree Accounting Solutions, an AAT-accredited practice in Govanhill, Glasgow. He works with sole traders, tradespeople, landlords and small limited companies across Glasgow and Clydebank.
This guide is general information based on UK and Scottish tax rules as at 13 October 2026. It is not personal advice. Rates and thresholds change, so speak to us about your own situation.