The short answer
Prepare for tax time by collecting sales records, purchase documentation, fees, shipping costs, refunds, business expenses, and inventory information. Reconcile the records and identify missing costs before sharing reports with your tax preparer. This U.S. checklist was reviewed October 6, 2026.
General U.S. recordkeeping information for preparing your 2026 records. This is not individualized tax advice or a filing checklist covering every situation. Ask your tax professional about your accounting method, deductions, and applicable federal and state requirements.
Gather the source records
The IRS allows a recordkeeping system suited to your business that clearly shows income and expenses. Reports should be backed by organized supporting documents.
- Marketplace sales and financial transaction reports.
- Inventory purchase receipts and acquisition notes.
- Shipping labels, fee details, refunds, and adjustments.
- Supporting documents for business expenses.
- Inventory records for items purchased, sold, and still held.
- Relevant mileage records and business-use documentation.
Resolve missing costs while you can still find the evidence
Review sold items with blank purchase costs. Check receipts, payment records, and purchase notes rather than inventing a number. Trace bulk buys back to the full purchase and document the allocation.
In GrimLister, Sales & Profit lets you add or correct purchase costs after a sale. Check that the item and source match the evidence before saving.
Reconcile before exporting
Use a consistent reporting period. Compare your sales and expense records with marketplace transactions and bank activity, allowing for timing differences and adjustments. Avoid counting a transfer between accounts as another sale.
Keep inventory estimates separate from realized proceeds. Ask your accountant how inventory and cost of goods sold should be treated under your method rather than assuming every purchase is immediately deductible.
Prepare the GrimLister handoff
Open Year-End Statements, select the relevant year, and review the period, missing-cost information, sales details, expenses, and inventory figures. Resolve gaps, then export the PDF and Excel files.
Give your preparer the reports together with the underlying records and a short list of unresolved questions. The export organizes information; it does not replace source evidence or file your return.
Keep the process going after tax season
Choose a regular review session to enter costs and expenses and resolve discrepancies while the purchases are still familiar. Preserve original documents in an orderly system by period and type.
Retention requirements depend on the record and circumstances. Follow current IRS guidance and your preparer’s advice rather than applying one blanket disposal date to everything.
Common questions
Does a year-end export mean my taxes are ready to file?
No. Check completeness and reconciliation, then have your tax professional apply the correct accounting method and tax treatment.
Does this checklist give the current 1099-K threshold?
No. It focuses on organizing records and does not rely on a reporting threshold to decide what records to keep or what income is taxable.