Documents for Self Assessment 2026/27: The Complete UK Checklist

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Table of Contents

Core Information: What Documents for Self Assessment Everyone Needs
The Importance of Record Keeping
References

As the 31 January filing deadline approaches, organisation is the key to a stress-free Self Assessment. Filing an accurate tax return is a legal requirement, and it depends entirely on having the correct documents and information to hand. Failing to prepare can lead to mistakes, which may result in penalties or an HMRC enquiry.

This guide provides a comprehensive checklist of the essential documents for Self Assessment, helping you report your income correctly and claim all the reliefs you are entitled to.

Core Information: What Documents for Self Assessment Everyone Needs

Before you begin gathering income and expense documents, make sure you have these fundamental details ready:

Unique Taxpayer Reference (UTR): Your 10-digit UTR is essential for identifying your tax record.
National Insurance Number.
Government Gateway User ID and Password: Needed for filing online.

Documents for Different Income Sources

Your tax return must include all sources of taxable income. Gather the relevant documents for each category that applies to you.

Income Source	Documents and Records Required
Employment	• P60 ‘End of Year Certificate’: Shows your total pay and tax deducted for the tax year. • P45 ‘Details of employee leaving work’: Required if you left a job during the tax year. • P11D: Details any taxable benefits in kind, such as a company car or private medical insurance.
Self-Employment & Partnerships	• Records of all sales and takings: Invoices, business bank statements, and till rolls. • Records of all business expenses: Receipts, purchase invoices, and mileage logs. A detailed breakdown is needed, not just a single figure for ‘other expenses’. • CIS Vouchers/Statements: If you work in the construction industry, these show tax deductions made by contractors.
Rental Property Income	• Rental income records: Tenancy agreements and rent books. • Records of allowable expenses: Receipts for letting agent fees, repairs, mortgage interest statements, and service charges.
Savings & Investments	• Bank and building society statements: Showing gross interest received. • Dividend vouchers or statements: From UK companies and foreign investments. • Certificates for other investments: Such as gilts or securities.
Foreign Income	• Statements of overseas income: From pensions, employment, rental property, or investments. • Evidence of foreign tax paid: To claim any foreign tax credit relief.
Other Income	• Pensions and annuities: Statements from pension providers and the DWP for State Pension. • Taxable state benefits: Details of any taxable benefits received. • Capital Gains: Records showing the purchase and sale price of any assets sold, plus associated costs (e.g., stamp duty, legal fees).

Documents for Claiming Tax Reliefs and Allowances

To reduce your tax liability, you must have evidence for any reliefs you claim.

Pension Contributions: Certificates or annual statements from your personal or workplace pension schemes showing the gross contributions made.
Charitable Donations (Gift Aid): Records of all donations made to charities under Gift Aid.
Student Loan Repayments: Your P60 will show any repayments made through your employment. If you made voluntary repayments, you will need statements from the Student Loans Company.
Allowable Expenses: For employees claiming tax relief on work-related expenses, you need receipts for items like professional subscriptions, tools, or business mileage not reimbursed by your employer.

The Importance of Record Keeping

Under Self Assessment, every taxpayer is required to keep and preserve the records needed to make a correct and complete return. This is a legal obligation. HMRC has the power to request documents to check your tax position, so organised records are your primary evidence.

Generally, you must keep your records for:

At least 5 years after the 31 January submission deadline for the relevant tax year if you are self-employed or a landlord.
At least 22 months after the end of the tax year if you are not running a business.

These records include all the documents listed above: bank statements, invoices, receipts, and payslips. Spreadsheets and lists are useful summaries but are not a substitute for the original documents.

For detailed procedural guidance on completing the return forms, it is advisable to consult the HMRC Self Assessment Manual, particularly sections beginning SAM121001 regarding the receipt and processing of returns. Additional information on record-keeping requirements can be found in the Compliance Handbook..