Record each transaction
Keep purchase cost, sale amount, fees, shipping, refunds and dates. Retain receipts and the basis for allocating costs to bundles. Reconcile platform reports with bank deposits so that fees and withheld amounts are not mistaken for missing revenue or counted twice.
Understand the classification question
Selling personal possessions and buying inventory for profit can have different tax treatment. A platform reporting form is not itself a complete calculation of taxable profit or a statement that no other income must be reported. Review current IRS guidance for your facts and tax year.
Do not guess on deductions
Business expenses, inventory accounting and losses can have specific rules. Personal use, mixed-use items and missing purchase records complicate the analysis. A profit calculator is not a tax return. Ask a qualified tax professional about uncertain records or classification before filing.
Check other obligations
Sales-tax collection, permits and local business requirements depend on activity and jurisdiction. A marketplace's collection service may not cover every sale or obligation. Keep buyer information private and retain only what is necessary for records and compliance. Consult the relevant official state or local authority.
Do I report only what the platform deposits in my bank?
A deposit may already have fees, refunds or other amounts removed. Reconcile gross transactions and adjustments with the platform records before determining the proper tax reporting. The deposit alone is not a complete account of revenue or taxable profit, and rules depend on your circumstances.