Self Assessment checklist: documents to prepare
Prepare your Self Assessment records with a practical checklist for income, business costs, tax paid and changes. Keep sensitive documents out of enquiry forms.
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Identify the year before collecting records
Start with the tax year and the reason a return is required. The records should relate to the relevant dates. If several years need attention, keep each year in a separate folder and identify the outstanding return for each.
Write a short list of income sources and changes during the year. Employment, business income, property, investments and overseas income may need different evidence. Do not rely solely on last year’s return when the circumstances have changed.
Use the personalised Self Assessment checklist to organise the categories that apply. For help preparing the return, see Self Assessment support.
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A records checklist by category
| Category | Records to gather where relevant |
|---|---|
| Employment and pensions | P60s, P45s, income statements, tax deducted and relevant benefits information. |
| Self-employment | Sales records, expenses, statements and the figures for the business period. |
| Property | Rental statements, expense records, ownership details and any changes. |
| Savings and dividends | Statements showing income received and any tax information. |
| Asset disposals | Dates, proceeds, purchase costs and supporting documents for items sold. |
| Contributions and reliefs | Relevant pension contribution and donation records. |
| Overseas income | Statements, currency information and foreign tax records. |
| HMRC account | Notices, earlier return information and records of payments already made. |
This is a preparation list, not a decision that every item is taxable, reportable or eligible for relief. Some returns need additional evidence. HMRC’s pay and tax records guide explains the main record categories and links to detailed guidance.
Keep a note beside any figure you cannot explain. It is better to identify uncertainty than to copy a number from an earlier year.
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For a self-employed business
Bring the business records together before the personal return is prepared. Check that the records cover the whole period and all payment accounts. Include cash transactions and payment-platform records where relevant. Keep evidence for the business purpose of spending.
List missing invoices, unexplained transfers and items awaiting a decision. A statement confirms that money moved, but it may not explain the transaction. Read HMRC’s self-employed record checklist for the types of supporting evidence.
Our bookkeeping service can be discussed where records need preparation. The bookkeeping versus accounting guide explains why completed transaction records and a completed tax return are separate stages.
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When something is missing
- Name the missing record and the period it covers.
- Check whether the issuer can provide a replacement or export.
- Keep an explanation of what is known and what remains uncertain.
- Tell the accountant about the gap before the return is prepared.
- Discuss the correct treatment instead of inventing a figure.
Do not postpone the first conversation until every document is available. Explain the gaps and any approaching deadline. Equally, do not assume that an incomplete set of records is enough to submit an accurate return.
Keep the original files. If you correct a spreadsheet or replace a statement, make the change clear. A simple note explaining the difference can prevent the wrong version being used.
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Check the dates that apply to you
For 2025/26, the usual online Self Assessment deadline is 31 January 2027. Check any individual HMRC notice and the current official deadline guidance. Payment obligations and payments on account need separate consideration.
The preparation sequence is: identify the year → collect records → resolve questions → review the return → approve submission → keep the confirmation. Agree enough time for questions and review before a deadline.
If you need ongoing support, sole trader accounting covers the wider records process. If you are comparing quotes, read what affects accountant costs so you can describe the work consistently.
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Send an outline before sending documents
Your first enquiry only needs the tax year, income categories, record position and relevant dates. Do not include your UTR, National Insurance number, Government Gateway password or identity documents.
After the work is agreed, confirm the document route, authorisation process and who will review the prepared return. Keep a copy of the final submission and the records that support it. This guide is general preparation information and does not determine your tax position.