Rebuild the evidence from suppliers, bank records and other reliable documents, and tell the accountant what is missing. Do not invent costs. If figures remain uncertain near the deadline, check HMRC’s rules for estimates or provisional figures and correct them when the evidence arrives.
Try to replace the records
Ask suppliers for duplicate invoices, download bank statements and search email accounts or booking systems. Keep the reconstructed evidence in one place. A bank payment can help identify a transaction, but may not explain exactly what was bought or whether it was for business.
Mark what is uncertain
Prepare a list of missing items with the date, amount and explanation. Distinguish a figure you expect to confirm later from one that cannot be fully verified. Your accountant needs that distinction to consider how the return should describe the figures.
HMRC has guidance for estimated and provisional figures where records cannot be replaced. The return may need an explanation, and provisional figures need updating when actual figures become available.
Do not hide the problem until approval
The accountant should know the evidence limits before presenting the return for your review. Ask what can be supported, what needs more work and whether anything should be excluded.
Improve the routine afterwards
Capture documents regularly and check that uploads are readable. A photo of a receipt is only useful if it shows the relevant details.
Example: a supplier invoice is missing
A bank payment and order email can help identify the transaction. Ask the supplier for a duplicate and give the accountant the evidence available. Do not create a substitute receipt that pretends to be the original.
Is a round-number estimate acceptable by default?
No. Try to reconstruct actual figures first. If that cannot be done, tell the accountant why and keep the working behind any estimate. The appropriate disclosure and treatment depend on the circumstances.
What if I later find the document?
Tell the accountant whether the return has been submitted and how the confirmed amount compares with the figure used. A provisional amount is not meant to remain untouched once the actual information becomes available.
Next step: Send TaxSimba the records you have and a clear missing-record list, so the accountant can assess the next steps without guessing.
Create a replacement-evidence log
Illustrative preparation example.
For a lost receipt, record the supplier, date, amount, purpose and evidence requested. Attach a duplicate invoice or other reliable support if obtained. Mark unresolved items openly for the accountant rather than inserting a round-number expense with no explanation.
Check: Which amount is evidenced and which remains an estimate needing review?
| Check | Practical action |
|---|---|
| Can the original evidence be replaced? | Request supplier copies and recover bank, email or platform records first. |
| What exactly remains uncertain? | List the date, amount, purpose and evidence gap for each item. |
| Is the figure estimated or awaiting confirmation? | Agree the appropriate disclosure and follow-up rather than leaving a provisional figure indefinitely. |
Does a bank payment guarantee an expense claim?
No. It may not establish the item, business purpose or private-use split. Provide all available supporting context.
What if I find the receipt after filing?
Compare it with the amount used and tell the accountant. A correction or update may be needed depending on the difference and how the return was completed.
Download a checklist for this guide
- Make a transaction-level missing-record list.
- Request supplier or platform duplicates.
- Recover bank and email evidence.
- Document the basis of any unavoidable estimate.
- Track provisional figures until actual amounts are known.