FBA margin guides

Amazon FBA Fee Overcharges: How to Check Your Sizes and Get Refunded

Your FBA fulfillment fee is based on how big and how heavy Amazon thinks your item is. If Amazon measures it wrong, even by a little, the item can jump into a higher size tier. Then you pay the higher fee on every single sale, quietly, for as long as nobody catches it.

Why this one hurts more than most

A lost unit is a one-time loss. A fee overcharge repeats. An extra $1 on an item that sells 300 times a year is $300 gone, on just one SKU. Most sellers set their price once, see the fee, and never look at it again.

Signs your fee might be wrong

• The fee went up but nothing about your product or packaging changed.
• The size tier looks off. A small, light item showing as large standard or oversize.
• The same item costs different amounts across similar listings or variations.
• Your margin shrank with no price change and no new Amazon fee announcement.

How to check your own items

1. In Seller Central, pull your fee preview for your FBA items. It shows the dimensions and weight Amazon has on file for each one.
2. Measure a packaged unit yourself: length, width, height, and weight, exactly as it ships.
3. Compare. If Amazon's numbers are bigger or heavier than yours, check whether the difference pushes the item into a higher size tier.
4. Start with your best sellers. That's where an overcharge costs the most.

How to fix it and get paid back

1. Take clear photos of the packaged item on a scale and next to a tape measure, with the numbers visible.
2. Open a case with Seller Support asking Amazon to re-measure the item, and attach your photos.
3. Once the dimensions are corrected, ask for a refund of the extra fees you already paid. There's a limited window, so check Seller Central for the current deadline.

When Amazon says no

You may hear that the item was measured correctly or that the fee is valid. A calm reply with your photos, your exact measurements, and the size tier they should put the item in usually works better than starting a new case.