A useful Self Assessment checklist starts with your circumstances, rather than a folder of receipts. Your return may need to bring together business profits, employment income, dividends, property income and other items. Preparing only the bookkeeping can leave important information missing.
In this article
- List income sources and relevant changes
- Gather statements and expense evidence
- Resolve missing figures with your adviser
- Review the return before approval
The aim is to give whoever prepares the return a complete, traceable picture and enough time to resolve questions. Start by identifying the tax year and the sources of income you had during it. Then gather evidence, reconcile the figures and agree who will review, approve and submit the return.
Establish the year and the filing route
For the 2025–26 tax year, covering 6 April 2025 to 5 April 2026, the usual paper filing deadline is 31 October 2026 and the online deadline is 31 January 2027. The usual payment deadline is also 31 January 2027. Different circumstances or an HMRC notice can affect filing dates, so check your own position against HMRC’s deadlines guidance.
If this is your first return, confirm registration and access early. If you need to notify HMRC that you must file for 2025–26, the usual notification deadline is 5 October 2026; this also applies if you registered previously but did not need a return for 2024–25. Do not assume an old account is ready to use or that appointing an accountant removes your need to supply information. Keep your Unique Taxpayer Reference and National Insurance number available, but use an agreed secure channel rather than sending login credentials.
Sole traders and landlords should also check whether their current reporting falls within Making Tax Digital for Income Tax. Annual preparation and current-year digital reporting need separate attention; completing last year’s return does not resolve this year’s obligations.
Build a pack around the income you actually received
The following is a preparation guide, not a list of items every taxpayer must report.
| Area | Documents to gather | Question to resolve |
|---|---|---|
| Employment | P60, relevant P45s, benefit information and payslips where needed | Were there multiple employers or taxable benefits? |
| Self-employment | Sales records, receipts, bank exports and accounting reports | Which accounting method and period apply? |
| Property | Rent statements, agent reports and expense evidence | Are there joint owners or overseas properties? |
| Savings and investments | Interest statements and dividend vouchers | Are all accounts and investment platforms covered? |
| Pension contributions and donations | Contribution statements and Gift Aid records | Were amounts paid personally or by a business? |
| Asset disposals | Purchase and sale documents, dates and associated costs | Does a separate reporting deadline or specialist review apply? |
| Previous tax position | Prior return, calculation and HMRC statement | Have payments already made been allocated correctly? |
Include a short note about changes: a business started or stopped, a property sold, a move overseas, a new source of income or a change in partnership membership. A preparer cannot ask the right follow-up questions about a change they do not know happened.
Make business figures traceable
HMRC expects self-employed records to identify business transactions and support the profit calculation. Its record-keeping guidance covers sales, costs and supporting evidence, with additional information needed when using traditional accounting.
Before exporting your figures, reconcile each bank and payment account. Investigate transfers that appear as income, missing platform sales, duplicate costs and personal spending recorded as business expenditure. A payment processor’s net deposit may not equal sales: fees, refunds and withheld amounts can explain the difference.
Keep a separate list of unresolved items with the date, amount, supplier and question. “Business expense?” is less helpful than “Laptop used for client work and personal study; purchased in March; usage estimate available”. Do not conceal uncertainty by placing every unclear transaction in a miscellaneous category.
Confirm the accounting method rather than assuming all invoices belong in the year they were issued. HMRC explains the distinction between cash basis and traditional accounting in its business records overview. Your software report needs to match the method being used for the return.
An illustrative preparation problem
Imagine a self-employed designer who also had a part-time job and received dividends from a personal investment account. Their business bank is reconciled, but the initial pack contains only business income and expenses.
A short income checklist identifies the missing P60 and investment statement. A review also finds that transfers from personal savings were categorised as sales. The designer supplies the transfer references, corrects the bookkeeping and records a question about a partly private equipment purchase.
The lesson is not that every taxpayer needs a complicated process. A complete source list and a reconciliation can prevent a polished business report from being mistaken for a complete personal tax picture.
Review the draft before authorising submission
Ask for a clear list of outstanding assumptions. Read the income figures and expense treatment, confirm personal details and check that unfamiliar entries have been explained. Compare the tax calculation with the HMRC account separately: a calculation of liability and a statement showing payments and balances serve different purposes.
Request a payment schedule showing any balancing payment and payments on account. Keep the approved return, calculation, submission acknowledgement and supporting records together. Agree how new information discovered afterwards will be assessed rather than silently changing the bookkeeping alone.
Arrange help with a defined scope
Send EPOS a summary of your income sources, the relevant tax year, the state of your records and any approaching deadline. Tax support can then be discussed with preparation, review, submission and any specialist matters explicitly agreed. See the pricing page for the approach to fees, and ask for a quote based on your circumstances.