How Amazon Fulfillment Fees Actually Work

What people mean by 'Amazon fulfillment fees'

The phrase covers at least five separate charges, and most explainers only walk through one of them. The core one is the FBA fulfillment fee: what Amazon charges per unit to pick, pack, and ship an order, set by the product's size tier and weight, not its price. Stacked on top is a monthly storage fee, charged on the cubic feet your inventory occupies in a fulfillment center, and it runs higher in the October-to-December window than the rest of the year. If a unit sits unsold past 181 days, an aged inventory surcharge starts stacking monthly on top of standard storage. Separately, Amazon can charge a returns processing fee on qualifying categories, and a removal, disposal or liquidation fee if you ask Amazon to clear inventory instead of selling it.

"Amazon merchant fulfillment fees" is a different question. Merchant-fulfilled (MFN) means you pack and ship the order yourself, through Amazon's Buy Shipping or your own carrier account. There's no FBA fulfillment fee and no storage fee — you pay the standard referral fee on the sale plus whatever shipping actually costs you. Sellers running FBA and merchant-fulfilled listings side by side are really running two separate cost structures, not one fee with two names.

Storage fees: the one that creeps

Monthly storage fees are billed on cubic feet, calculated from average daily volume across the month, not a snapshot on one day. A pallet that sold down fast costs less than one that sat full for three weeks, even if the end-of-month total looks the same. The rate is seasonal too — higher for October through December — so stock that was cheap to hold in July can get quietly expensive to hold in November.

The aged inventory surcharge catches the most sellers, because it isn't a cliff-edge — it's a second monthly charge that starts at 181 days and adds to standard storage rather than replacing it. By the time a SKU has sat six months, you're paying storage and the surcharge on stock that's also tying up cash. That's the point where the decision is genuinely removal versus liquidation, not "wait and see."

Calculating your actual number

Amazon's Revenue Calculator gives a real figure for a specific product — it pulls size tier, weight and category and returns the fulfillment fee, referral fee, and an estimated storage cost together. Use it before you list, and enter your actual packaged dimensions, not the catalog default. This is where the number quietly goes wrong: catalog data can list an old package size or unboxed dimensions, and Amazon bills on the shipped package, dimensional weight included.

Full Circle has managed more than $500M in revenue across 100+ brands, and dimensional-weight misclassification shows up across that book as one of the most common leaks — not fraud, just a package redesign that never made it back into the listing.

When the fee is wrong, or won't stop climbing

Sometimes the calculator number and the invoice don't match, and the gap is real, not rounding. Start with the package dimensions and weight Amazon has on file for the ASIN versus what's on the box today — that mismatch is the single most common cause. If dimensions are right and the fee is still off, that's a case for Seller Support with the shipment ID and current package measurements, not a debate about the rate itself.

We've also missed a reimbursement window ourselves — Amazon caps how far back a lost or damaged unit can be claimed, and if a discrepancy report sits unreviewed too long, the window closes before anyone acts on it. The fix isn't a smarter dispute; it's checking discrepancy reports on a schedule instead of only when a number looks unusually high.

If the problem is really margin, not fees — ad spend eating the gap while rank needs defending — that's usually a leak in the ad account, not the warehouse, and it's worth diagnosing separately rather than blaming fulfillment for it. That's Dr. PPC's territory.

Canada, and other fulfillment programs

Amazon Canada fulfillment fees follow the same structure — a per-unit fee by size and weight, monthly storage by cubic foot, an aged inventory surcharge past 181 days — but the rate card is separate and billed in CAD, not a currency conversion of the US schedule. If you're comparing the same product across amazon.com and amazon.ca, run each through that country's own calculator; converting one figure by exchange rate gets you close, and close is the wrong standard when you're setting price.

Amazon Warehousing and Distribution (AWD) is a separate bulk-storage option with its own pay-as-you-go pricing and no seasonal surcharge, built to feed inventory into FBA rather than replace it. It can lower total storage cost for sellers holding large volumes, but it's its own program with its own enrollment, not a discount inside standard FBA storage.

Where this fits into Dr. Stock

Dr. Stock is inventory and fee monitoring for Amazon sellers, run by Fable 5 out of Full Circle — not a 3PL, since it doesn't store or ship anything itself, and not a full inventory system, since it doesn't replace your ERP or multichannel stack. What it watches for is exactly what's described above as it happens: storage and aged-inventory charges creeping past the point of no return, FBA fee errors and dimensional-weight misclassification, shipment discrepancies and reimbursement windows, and the removal-versus-liquidation call before it gets made by default. The client sets how much of that runs on autonomy; purchasing decisions always go to a human. There's no published price — it's a demo call, with the first 30 days free. Whether or not that's the right fit, running your own numbers through Amazon's calculator with real package dimensions is the first move either way.