Amazon FBA Fees Explained: Where Your Margin Actually Goes

Sellers rarely lose money on one big fee. They lose it on seven small ones that never appear on the same screen. Here is the whole stack, in the order it hits your settlement.

1. Referral fee

Amazon’s commission on the total sale price, charged on every unit in every fulfillment method. Most categories sit at 15%; a handful are lower and a few are tiered by price point. This is the one fee you cannot engineer away — only out-price or out-margin.

2. Fulfillment fee (FBA)

Pick, pack and ship, priced by product size tier and shipping weight. Two consequences worth internalizing: dimensional weight can matter more than actual weight, and the boundary between size tiers is where money is won or lost. Re-measure your packaging — a slimmer box has moved more products back into profit for my clients than any ad change.

3. Monthly storage

Charged per cubic foot of daily average volume, and materially higher in the Q4 months. Slow movers in large boxes are the classic silent loss: they pay rent every month and sell twice a quarter.

4. Aged inventory surcharges

Inventory sitting past the long-term thresholds picks up extra charges on top of storage. If a SKU is not turning, the decision is liquidate, remove or discount — not wait.

5. Inbound placement and low-inventory fees

Amazon now prices behaviour, not just storage: how you split shipments across the network, and whether you keep enough cover for demand. Both are avoidable with planning, and both show up as unexplained margin loss when they are not.

6. Returns processing and unsellables

In several categories the return itself carries a processing fee, and a returned unit often comes back unsellable. Track your true return rate by SKU. Category averages are useless here.

7. Removals, disposals and reimbursements

Getting inventory out costs money too. And on the other side, Amazon owes reimbursements for lost and damaged units far more often than most sellers realize — if nobody reconciles it, nobody claims it.

How to audit yourself in an afternoon

1. Pull your fee preview and settlement reports for the last full month.
2. Build contribution margin per unit per SKU — not per order, not per brand.
3. Sort ascending. The bottom fifth is where your cash is going.
4. For each: re-measure the package, re-check the size tier, re-check the return rate, and decide raise price / shrink box / liquidate.
5. Repeat monthly. Fee schedules change; your spreadsheet from last year is fiction.

Always verify the current numbers against Amazon’s own fee schedule in Seller Central before you make a decision — the structure below changes more often than the headlines suggest.

The per-SKU worksheet, the size-tier checklist and the reimbursement audit steps are in the Amazon Seller’s Pocket Guide. Unsure of a term? The glossary is free. And if you have not yet run the go/no-go math, start with the honest numbers post.