1. Why record keeping matters
GOV.UK says self-employed people need records of business income and expenses for Self Assessment. Records help work out profit or loss and support the figures if HMRC asks to see them.
Accuracy and the ability to identify business transactions matter more than a decorative filing system.
2. Sales and income
Keep records of all sales and business income, not only amounts that arrived by one payment method. Connect income to invoices, receipts or other evidence so the transaction can be identified.
3. Business expenses
Record business expenses and retain appropriate proof such as receipts, supplier invoices or bank records. Whether a cost is allowable for tax is a separate question that may require current HMRC guidance or professional advice.
4. Invoices and supporting evidence
Keep issued sales invoices and evidence for purchases. GOV.UK lists examples including receipts, bank statements, chequebook stubs, sales invoices, till rolls and bank slips.
5. VAT and PAYE where applicable
Keep VAT records if registered for VAT and PAYE records if you employ people. Those systems have additional rules, so do not assume a general job-management export satisfies them.
6. Outstanding amounts and payments
Keep invoices, partial payments and outstanding balances understandable. Businesses using traditional accounting may need additional information about amounts owed or committed at the accounting period end; check the method and guidance that apply to you.
7. Keep personal and business information understandable
Make it possible to identify business transactions even if a bank account or purchase has mixed use. Record the business purpose and relevant business proportion rather than relying on memory at return time.
8. Organise digital records
Use consistent folders or systems, stable document names and a routine for capturing evidence. Access control and backups matter because a tidy record is not useful if it is lost or exposed.
9. Backups and exports
Keep recoverable copies appropriate to the importance of the records. Test that exports open and contain what you expect; an export is a source record, not automatically a submission accepted by HMRC.
10. Monthly review checklist
Practical checklist
- Sales and income records are complete
- Expenses have evidence and a clear purpose
- Invoices and payments reconcile to the records
- Outstanding balances are reviewed
- VAT or PAYE records are updated where applicable
- Digital records are backed up
- Retention dates follow current guidance
11. Check current HMRC requirements
GOV.UK currently says sole traders generally keep records for at least five years after the 31 January submission deadline for the relevant tax year, with different treatment in some situations such as very late returns. Always check the current page for the rule applying to your records.