The 5 Bookkeeping Mistakes That Distort Every Amazon Seller's Margins

An Amazon deposit is not revenue. It's gross sales minus referral fees, FBA fees, storage fees, refunds, advertising, and reserve adjustments — often spanning two settlement periods. Booking the net deposit as revenue understates both your sales and your costs, making your revenue look smaller and your margins look larger than reality. Every downstream metric — conversion economics, ad efficiency, valuation multiples — inherits the distortion.

Amazon holds rolling reserves that can swing thousands of dollars between settlements. Ignore them and your months become noise — a 'bad month' that's actually just a reserve increase, a 'great month' that's a release. Reserves belong on the balance sheet, not lost in revenue.

Fee blindness is subtler: lumping all Amazon charges into one 'Amazon fees' expense line. Referral fees scale with price, FBA fees with size and weight, storage fees with velocity, advertising with strategy. Blend them and you can't see that your storage fees doubled or that one oversized product's fulfillment cost quietly ate its margin.

True product cost is landed cost: unit price plus freight, duties, prep, and inbound shipping. Sellers who expense inventory at purchase, or use supplier unit price as COGS, are running on fictional margins — usually optimistic ones. Monthly inventory valuation with landed costs is non-negotiable at scale.

Finally, Amazon loses and damages inventory constantly, and its automatic reimbursements are incomplete. Sellers who don't systematically monitor reimbursement claims routinely leave four and five figures unclaimed. It's the closest thing to free money in the FBA business — we found $14K for one client during onboarding alone.

If any of these five sound familiar, your margins deserve a second opinion. A settlement-accounting clean-up typically pays for itself in decision quality within a quarter.