---
title: Missing Self Assessment Documents? 2026/27 Evidence Guide
description: Missing a P60, bank statement, invoice or investment report does not automatically justify filing Self Assessment late. First reconstruct the evidence from employers, online accounts, banks and platforms. If a final figure genuinely cannot be obtained by the deadline, HMRC…
url: "https://www.accountingfirms.co.uk/knowledge-bank/what-documents-do-you-need-for-self-assessment/"
updated: "2026-08-12"
category: Self Assessment Tax Return
---

# Missing Self Assessment Documents? 2026/27 Evidence Guide

Missing a P60, bank statement, invoice or investment report does not automatically justify filing Self Assessment late. First reconstruct the evidence from employers, online accounts, banks and platforms. If a final figure genuinely cannot be obtained by the deadline, HMRC can accept a reasonable provisional or estimated figure when it is clearly explained and later corrected where necessary.

This 2026/27 guide focuses on replacement evidence and safe use of estimates. For the standard preparation list, use our [complete Self Assessment documents checklist](https://www.accountingfirms.co.uk/knowledge-bank/documents-for-self-assessment/).

## Provisional versus estimated figures

| Type | Meaning | What happens next |
| --- | --- | --- |
| Provisional figure | Your best current figure while waiting for final information | Replace it with the accurate amount as soon as available |
| Estimated figure | A reasonable amount intended as final because exact records cannot be recreated | Keep the reconstruction and explain why estimation was necessary |

Both must use all information reasonably available. A round number chosen for convenience is not a defensible estimate.

## Lost P60 or employment income details

Ask the employer for a replacement P60 or a written statement of pay and tax. Check:

- the HMRC personal tax account or app;
- final payslips and cumulative pay figures;
- P45 documents if employment ended;
- P11D or payrolled-benefit records;
- bank statements as supporting—but not complete—evidence.

Net salary deposits do not show gross pay, PAYE tax, employee pension deductions or taxable benefits, so do not gross them up without reliable corroboration.

## Missing P45

A former employer should provide a P45. If it is unavailable, use the final payslip and HMRC employment record. A new employer can operate a starter checklist without the original P45, but this does not remove the need to report accurate annual pay and tax.

## Bank and savings interest

Download annual interest certificates or statements from every bank and building society. HMRC may receive interest information, but your return remains your responsibility and joint-account allocations can differ. Reconstruct closed accounts through archived online statements or a formal bank request.

## Dividend and investment reports

Obtain consolidated tax certificates, dividend vouchers and broker transaction histories. Separate:

- UK and foreign dividends;
- interest and offshore fund distributions;
- ISA transactions, which are normally tax exempt;
- equalisation and accumulation amounts;
- capital disposals, fees and acquisition costs.

A portfolio valuation does not replace an income tax certificate or CGT transaction report.

## Sole-trader records

Rebuild missing business records from sales platforms, merchant processors, VAT returns, invoices, bank feeds, supplier statements and customer confirmations. Reconcile turnover across sources and remove internal transfers, loans and capital introduced.

For expenses, use duplicate invoices and account histories. Do not estimate a fixed percentage of sales unless it reasonably represents evidenced costs and the method is documented.

## Property income

Request annual statements from letting agents and reconcile them to rent received. Collect tenancy agreements, mortgage-interest statements, insurance, service charges, repairs and legal costs. Distinguish refundable deposits, capital improvements and residential finance costs.

## Cryptoasset records

Export every exchange and wallet history before accounts close or retention periods expire. Record wallet addresses, transaction hashes, sterling valuations and Section 104 pools. Exchange gain reports can omit transfers and off-platform acquisitions; use our [crypto tax checklist for accountants](https://www.accountingfirms.co.uk/knowledge-bank/cryptocurrency-tax/) for reconstruction controls.

## Foreign income evidence

Obtain foreign payslips, bank interest, dividend vouchers, pension statements, rental accounts and tax assessments. Convert amounts to sterling using a consistent, supportable exchange rate and keep evidence of foreign tax paid. Delayed foreign assessments can justify provisional figures, but the return should identify what remains outstanding.

## Pensions and relief claims

Collect pension statements showing gross contributions and the relief method, plus Gift Aid records. Bank payments alone may not show whether tax relief was added at source. For workplace schemes, determine whether contributions were net pay, relief at source or salary sacrifice.

## Capital gains evidence

- purchase and sale contracts;
- broker contract notes;
- legal and professional fees;
- improvement invoices;
- probate or gift valuations;
- share reorganisations and corporate actions;
- previous loss claims.

If a valuation is required, document the valuation date, method, comparable evidence and professional opinion.

## How to use a provisional figure correctly

1. Take every reasonable step to obtain the final data.
2. Calculate the best figure from the evidence available.
3. Complete all relevant return boxes normally.
4. Explain in the “Any other information” section which figures are provisional, why and when final information is expected.
5. Pay tax based on the best estimate.
6. Amend the return promptly when final figures arrive.

Do not file a blank section or omit an income source because its exact amount is unknown.

## Amendment and interest consequences

A taxpayer normally has 12 months after the statutory filing deadline to amend a Self Assessment return. If the final figure increases tax, interest can run from the original payment due date. If it reduces tax, a repayment and repayment interest may arise.

Leaving a provisional figure unresolved can prompt an HMRC enquiry. After the amendment window, overpayment relief or HMRC discovery rules may apply, but they are not substitutes for timely correction.

## Evidence pack for an HMRC enquiry

- requests made to obtain replacement documents;
- source data used for reconstruction;
- calculation spreadsheets and assumptions;
- comparison with prior and later years;
- explanation included on the filed return;
- date final information arrived;
- amended return and payment confirmation.

## Official guidance

- [GOV.UK: keeping and reconstructing tax records](https://www.gov.uk/keeping-your-pay-tax-records)
- [GOV.UK: provisional figures and amending returns](https://www.gov.uk/self-assessment-tax-returns/sending-return)
- [HMRC: provisional and estimated figures](https://www.gov.uk/hmrc-internal-manuals/self-assessment-manual/sam121190)
- [GOV.UK: correcting a Self Assessment return](https://www.gov.uk/self-assessment-tax-returns/corrections)

*This guide is general information for 2026/27. Estimates must be reasonable, evidenced and clearly disclosed.*