Essential Documents to Keep for Your Self-Assessment Tax Return Claims Explained

HMRC requires taxpayers to keep records that support everything reported on their Self-Assessment return, including:

• Income
• Allowable expenses
• Capital gains
• Pension contributions
• Investment income
• Rental earnings
• Foreign income
• Student loan deductions
• Charitable donations

Official record-keeping rules:
👉 https://www.gov.uk/self-assessment-tax-returns/keeping-records

These records must be kept for:

• 5 years after the 31 January deadline (self-employed and partnership returns)
• 1 year after the filing deadline (employment-only taxpayers, unless HMRC opens an enquiry)

But best practice — and what accountants recommend — is to keep them for 6 full years, the maximum period HMRC can review for careless errors.

1. To Support Claims for Allowable Expenses

If you claim expenses, HMRC can ask for proof. Without receipts or invoices, your claims may be disallowed.

2. To Avoid Penalties

If you cannot provide documentation during an enquiry, HMRC may issue penalties for:

• carelessness
• inaccuracies
• under-reporting
• insufficient records

Penalties can range from 0%–100% of the tax due.

3. To Ensure Accurate Tax Reliefs

Pension contributions, Gift Aid, mileage claims, and work-related expenses all require evidence.

4. To Protect You During an Enquiry

HMRC enquiries are becoming more automated. Clear records reduce risk and speed up resolutions.

5. To Prevent Overpayment of Tax

Good documentation ensures you claim everything you are entitled to.

You must keep complete evidence of every type of income you receive.

Employment Income

• P60 (end-of-year summary from employer)
• P45 (if you leave a job)
• P11D (employee benefits)
• Monthly payslips
• Bonus or commission statements

More guidance:
👉 https://www.gov.uk/tax-codes

Self-Employment Income

• Sales invoices
• Receipts
• Bank statements
• Cashbooks
• Online payment platform statements (PayPal, Stripe, Etsy, Uber, Airbnb)

For MTD compliance, records must be digital.

Rental Income

• Tenancy agreements
• Rental income statements
• Deposit records
• Letting agent statements
• Rent receipts
• Mortgage interest statements
• Repairs and maintenance invoices

More info:
👉 https://www.gov.uk/renting-out-a-property/paying-tax

Investment Income

• Dividend vouchers
• Interest statements from banks
• ISA statements (for reference)
• Stockbroker statements
• Cryptocurrency transaction history

Foreign Income

• Statements from foreign employers
• Foreign rental income records
• Overseas pension documentation
• Bank statements showing international payments

You may need translations for foreign documentation.

You must keep evidence for every expense you claim.

Allowable Business Expenses

For self-employed individuals:

• Office supplies
• Travel receipts
• Vehicle mileage logs
• Software subscriptions
• Marketing invoices
• Professional fees
• Utility bills (if using home as office)

Mileage must be logged with:

• date
• starting location
• destination
• business purpose
• total miles

Rental Property Expenses

• Repairs and maintenance invoices
• Utility bills (if landlord pays)
• Ground rent and service charges
• Insurance policies
• Letting agent fees
• Replacement of domestic items receipts

Charitable Donations (Gift Aid)

• Donation receipts
• Charity confirmations
• Monthly direct debit statements

These allow you to claim Gift Aid through Self-Assessment.

Pension Contributions

• Statements from pension providers
• Annual benefit summaries
• Evidence of private pension payments
• Letters confirming tax relief

This is vital for higher- and additional-rate taxpayers.

Professional and Union Fees

• Membership receipts
• Subscription confirmations

Some fees are tax-deductible only if approved by HMRC.

Full list here:
👉 https://www.gov.uk/government/publications/professional-bodies-approved-for-tax-relief-list-3

If you sell:

• cryptoassets
• shares
• second homes
• investments
• businesses

…you must keep:

• purchase documents
• sale documents
• improvement cost receipts
• broker statements
• transaction logs

Guidance:
👉 https://www.gov.uk/capital-gains-tax

Especially post-2020, HMRC checks:

• SEISS grant letters
• Local authority grant statements
• Bounce Back Loan documents
• COVID support scheme summaries

These must match your tax return entries.

HMRC often requests bank statements to verify income and expenses.
Keep:

• Business account statements
• Personal account statements (if business expenses were paid personally)
• PayPal / Stripe / Wise / Revolut statements

HMRC accepts:

• Digital records
• Scanned receipts
• Photographs of receipts
• Emails confirming payment
• Online banking records

You do not need to keep original paper receipts — as long as digital copies are clear and legible.

This is why tools like Dext, Hubdoc, QuickBooks receipt capture, Xero Files are recommended.

If you can’t produce documentation during an HMRC enquiry, they can:

• Disallow your expense claims
• Adjust your income figures
• Recalculate tax owed
• Charge penalties
• Add interest
• Extend their review to multiple years

Poor documentation is one of the biggest reasons people overpay tax.

At Loyals, we help clients reconstruct missing records where possible and maintain fully compliant digital evidence systems.

1. Store Everything Digitally

Use cloud accounting software and receipt scanners.

2. Keep Separate Personal and Business Accounts

This simplifies categorisation and reduces errors.

3. Record in Real Time

Don’t wait until January — document as you go.

4. Review Quarterly

Catch mistakes early instead of at year-end.

5. Get Professional Oversight

Accountants can detect missing evidence before HMRC does.

A marketing consultant had claimed £4,000 in travel expenses but kept no receipts.
During an HMRC enquiry:

• 60% of the expenses were disallowed
• She owed £1,400 in additional tax and interest
• Her risk profile with HMRC was marked as “medium risk”

After moving to Loyals, she now uses digital tracking — zero issues since.