In short: Compare the dimensions and weight Amazon has on record with your real packaged product, starting with best sellers. Request a remeasurement where Amazon is wrong, ask for past overcharges back, and check reimbursements monthly because claim windows are short.
On one account, we found FBA fees being charged incorrectly across multiple SKUs. Correcting them saved roughly $5,000 a month, about $60,000 a year, with no change to advertising, pricing or sales volume. The only thing that changed was that someone checked the fees against the product.
That's typical. Fulfillment fees are charged automatically on every unit, they're easy to assume are correct, and a small error repeats thousands of times a month. Here's how to check yours.
Why FBA fees go wrong
Amazon calculates the fulfillment fee mainly from the size tier and shipping weight it has on record for each product, along with its price band. Those numbers can drift from reality in a few ways:
- Measurement at receiving. Amazon measures units as they arrive. A bowed carton, a bulging poly bag or a label can produce a reading slightly larger than the product's real dimensions, and a fraction of an inch near a tier boundary changes the fee on every unit.
- Packaging changes. A supplier switches board stock or adjusts a box between production runs. The new packaging is genuinely bigger or heavier, and nobody updated anything. In this case Amazon is right and the fix is the packaging.
- Dimensional weight. For larger items Amazon bills on the greater of actual weight and dimensional weight, so a small dimension change can push the billable weight up even when the product weighs the same.
The audit, step by step
1. Pull Amazon's numbers for every SKU
Download the FBA fee preview report from the fulfillment reports in Seller Central. It lists the dimensions, weight, size tier and estimated fulfillment fee Amazon has on record for each product. Save it with the date so you have a baseline to compare against next time.
2. Measure your own packaged units
Start with your best sellers, since that's where an error costs the most. Measure the product as it ships, in its packaging, and weigh it. Compare against Amazon's record. Flag anything that differs, and anything within about half an inch of a size tier boundary.
3. Look for fee changes without price changes
Compare the fee per unit month over month for each SKU. If the fee moved and you didn't change the product, the price or the packaging, the most likely cause is a remeasurement. Profit tools that track fees per order, like Sellerboard, make this much faster than working from settlement reports.
4. Request a correction, and the refund separately
Where Amazon's record is wrong, open a case asking for the product to be remeasured. Include your own measurements and photos of the packaged unit against a tape measure and on a scale. Correcting the dimensions fixes future fees, but it doesn't automatically refund what you've already been overcharged, so ask for reimbursement of past overcharges as part of the same effort. Eligibility windows for fee claims can be short, so check the current rules in your account's Help pages and act quickly once you find a problem.
5. If Amazon is right, fix the packaging
Sometimes the measurement is accurate and the packaging is simply larger than it needs to be. A redesign that brings a product under a tier boundary can be worth more than any dispute.
Don't stop at fees: reimbursements
Lost, damaged and mishandled inventory is the other place sellers leave money with Amazon. Amazon now reimburses many units lost in its fulfillment centers automatically, but not everything is caught, and the windows for filing claims got much shorter in late 2024. As of that update, the commonly reported windows include:
| Situation | Claim window (as reported after the October 2024 update) |
|---|---|
| Lost or damaged in a fulfillment center | 60 days |
| Customer returns not received or not credited correctly | 60 to 120 days after the refund or replacement |
| Removal shipments lost in transit | 15 to 75 days after the shipment was created |
Amazon changes these policies. Confirm current windows and how reimbursements are valued in Seller Central before relying on them.
Short windows mean this can't be a once-a-year project. A monthly check of inventory adjustments, returns and removals catches most of it in time.
Stranded and suppressed inventory
Inventory that's sitting in a fulfillment center attached to a listing that can't sell is still costing you storage fees. Check stranded inventory and suppressed listings at least weekly, fix the listing issue, and get the stock selling again before it ages into higher storage charges.
A routine that keeps it fixed
- Monthly: compare fee per unit by SKU against last month, and review inventory adjustments, returns and removals for claims.
- Every new production run: measure and weigh the packaged product before it ships to Amazon.
- Weekly: stranded inventory and suppressed listings.
- Twice a year: a full SKU-level profitability review, so you know what each product actually earns after every fee.
Why this matters more than it looks
Fee errors don't only cost the overcharge. Your margin per unit sets how much you can afford to spend on advertising. An overcharged product has an artificially low break-even ACoS, so it gets bid too cautiously, sells less, and ranks lower. Fixing fees often unlocks growth as well as savings. We explain that link in how to improve TACoS without sacrificing growth.
This is how we approach profitability for clients. See profitability and fee audits.
Sources
- Helium 10, Amazon FBA inventory reimbursement policy update.
- Velocity Sellers, The true cost of an FBA remeasurement (September 2026).
- Amazon, FBA reimbursements support page.