Many resellers only think about taxes when the marketplace sends a summary or their preparer asks for totals. That is usually when the missed deductions show up. The fix is not a bigger spreadsheet. It is a repeatable checklist and cleaner bookkeeping during the year.
This list is not tax advice for every business type, but it is a strong starting point for the categories resellers most often forget to track. Use it as an operating checklist and confirm the final treatment with your tax preparer.
Selling costs
- Marketplace fees, promoted listing spend, and payment processing fees
- Refund-related fees you absorb as part of selling
- Packaging materials such as boxes, tape, labels, and mailers
Logistics costs
- Postage, shipping labels, insurance, and signature confirmation
- Mileage for sourcing trips, post office runs, and local inventory pickups
- Travel tied directly to sourcing or inventory management
Operating costs
- Storage units, shelving, bins, and workspace organization supplies
- Software subscriptions for bookkeeping, inventory, and repricing
- Business-use share of phone, internet, and home office expenses
- Bank, card, and accounting fees on accounts used for the business
The real risk is not the deduction itself
The bigger issue is usually documentation. If you cannot tie a deduction back to a clean category, a receipt, or a business reason, it turns into a year-end scramble and your confidence drops fast.
That is why sellers who switch to a bookkeeping workflow early often save more time than money first. You stop rebuilding the same evidence trail every quarter.
This article is general information, not tax or legal advice. Confirm the treatment for your business with a tax professional.