Amazon measured it bigger. Every unit pays for it.
Amazon charges your FBA fulfillment fee on its own measurements of your product. When it decides a box is bigger or heavier than it is, the fee goes up on every unit after that, quietly. MyProfit checks the fee on every order and tells you when it happens, with the case text to get it fixed.
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Now: 14.00 × 10.00 × 7.00 in, 3.10 lb · fee up $1.62 a unit
Why your FBA fee can be wrong
The fulfillment fee depends on the size tier and shipping weight Amazon has on file for each product. Amazon measures products itself, and sometimes gets them wrong: a box measured an inch longer, or weighed with the wrong packaging, can move a product into a bigger tier or a heavier band. A $1.62 difference on a product that sells 40 units a month is $778 a year.
Amazon has a re-measurement and reimbursement process for this, but you have to notice first. The fee is one line among dozens on each settlement, and it changes for other reasons too: Amazon's fee changes on January 15, the holiday peak rates from October 15 to January 14, the price band, and the low-inventory-level fee, which Amazon adds to the same line.
How it works
- Connect Amazon. Approve MyProfit in Seller Central. We never see your Amazon password.
- MyProfit compares, every week. It loads Amazon's fee preview (the measurements, size tier and fee Amazon has for each product) and the fulfillment fee charged on every order in your settlements of the last 12 months.
- It flags real overcharges. A product counts when Amazon's measurements grew and its fee went up, or when you're charged above the product's usual rate and Amazon's own preview confirms the higher fee. Fees are compared within one fee season and price band, and a week when half your products go up is treated as Amazon's own fee change.
- You file, with the text ready. Each finding has case text with the before and after measurements. Copy it into Seller Central and mark it filed.
What it leaves out, on purpose
A fee that went up for a while and came back down is often Amazon's low-inventory-level fee, not a measurement. Those are shown as worth checking and left out of the total, so the number you see is what Amazon's measurements explain. You can also enter your own package size next to a product and see both size tiers by Amazon's rules.
Want to check one product by hand first? The FBA fee calculator gives the 2026 fee for any size and weight, and Amazon seller fees in 2026 lists every other fee.
Questions
Which sellers does it work for?
FBA sellers on Amazon US. It needs Amazon's fee preview and your settlements, which MyProfit loads for the US.
What does it cost?
Nothing. The fee check is on the free plan, with no commission on what Amazon refunds. The Seller plan ($19.99 a month) adds profit by product and payout, PPC, returns, sales tax and your accounting export.
Does it also find refunds Amazon never reimbursed?
Yes, that's the FBA reimbursement finder, on the same free plan.
How soon will I see results?
Amazon makes the fee preview report at most once a day and takes up to three days to deliver it. The first check runs once it arrives, and the comparison of two weekly previews (Amazon remeasured it) needs a second one a week later.
See which products Amazon is overcharging
Connect your Amazon account and the fee check starts with Amazon's next fee preview. Free, with no commission.