Make the loss map narrow enough to act on
Record the event and affected period, systems and document families. “All accounting lost” is less useful than “March–June invoices missing; bank statements intact; prior return and depreciation schedule missing.” Preserve surviving copies before rebuilding totals.
The IRS recordkeeping guidance links books to supporting documents for purchases, sales, payroll and other transactions. The IRS reconstruction guidance gives recovery routes after a disaster or casualty. Its recovery ideas can organize a missing-record file, but disaster relief, fee waivers and valuation rules are not automatically available for ordinary lost files.
Recover from sources that held the original event
- Suppliers: request duplicate invoices, statements and delivery records for the missing period. Record who provided them and the original invoice references.
- Banks and payment processors: recover full statements and settlement reports, including fees, refunds and chargebacks. Net deposits alone may omit gross sales or include non-sales transfers.
- Preparers and bookkeepers: request filed returns, submission evidence, workpapers, opening balances and asset schedules. A transcript and a full return copy are different records.
- Assets and property: locate purchase agreements, lender records, insurance schedules, photos and improvement invoices. An insurance amount is not automatically tax basis or fair market value.
- Internal backups: preserve recovered emails, original exports and file versions. Keep an untouched source copy and note the recovery date.
Use three evidence labels
Recovered copy: a duplicate of an identifiable original from a credible source. Reconstructed: a record assembled from named surviving evidence. Estimate: an approximation with assumptions and limitations. These are organizational labels, not a guarantee that an expense or loss is deductible.
For each gap, record the fact needed, substitute obtained, coverage and remaining uncertainty. If no evidence supports an amount, leave it unknown; do not create an invoice or backdate a document. The reviewer decides whether available support is sufficient for the specific tax or business purpose.
Fictional reconstruction: separate the deposit components
Harbor’s bank shows USD 2,700 received. A recovered processor statement shows USD 3,000 customer charges, USD 400 refunds and USD 100 fees, producing USD 2,500 net settlement. Another document identifies a USD 200 owner transfer. The bridge is 3,000 − 400 − 100 + 200 = 2,700.
Calling the entire USD 2,700 “sales” would mix a transfer with net operating receipts and hide refunds and fees. This bridge demonstrates reconciliation only; it does not establish when income is recognized, how each item is taxed or whether all transactions have been recovered.
If the processor statement covers only half the month, mark the coverage gap. A matching total can still be incomplete or coincidental; reconcile dates, transaction references and opening/closing balances as well.
Your private worksheet
Keep this record with your own source files. There is nothing to enter or upload here. Copy the headings, or open the plain-text sheet to save locally.
- Loss map
- Affected period/system/document family; missing item; surviving source and business/tax question affected.
- Recovery request
- Source holder, document requested, coverage dates, request/result dates and exact file received.
- Evidence label
- Recovered copy/reconstructed/estimate; origin, assumptions, coverage and limitations.
- Reconciliation
- Gross events, refunds, fees, transfers, net bank amounts and unexplained differences with source IDs.
- Unresolved gap
- What remains missing, why it matters, reviewer decision and next evidence needed; never fabricate a source.
Two fictional files to compare
Invented examples with no real applicant, taxpayer number or live account.
Only a bank statement survives
Cedar wants to recreate expenses from merchant names in debits.
Review result: Recover invoices and purpose evidence. A debit can show money moved without proving what was purchased or its tax treatment.
The totals match but dates do not
Harbor’s reconstruction matches a month-end total using a processor export from a different period.
Review result: Keep the mismatch open and obtain the correct coverage. Matching totals alone do not establish the right transactions.
What completes this review?
The reconstruction is ready for review when each amount links to recovered evidence or an explicitly labeled assumption and the remaining gaps are visible. Set an archive plan separately so the recovered records are not lost again.
Official sources
Checked November 4, 2026. A review date is not a form revision. Recheck current instructions and updates before acting; the worksheet is an organizational aid.