Amazon FBA Fee Overcharge: How to Spot a Wrong Size Tier and Get Your Money Back

Written by the BidVentor Editorial Team. Reviewed by Adeel Imrani, founder of BidVentor (14 years growing a $2M beauty brand on Amazon, $30M+ ad spend). Last updated November 2026.

Quick answer

An Amazon FBA fee overcharge usually happens when Amazon has the wrong weight or dimensions on file for a product, which pushes it into a bigger size tier and a higher fulfillment fee on every unit. To catch it, compare the fulfillment fee each SKU pays today with what it paid a few weeks ago and with the size tier you expect from your own measurements. If the numbers do not match, request a remeasurement in Seller Central, and once Amazon confirms the correct size, open a case asking for the overcharged fees back. Move quickly: Amazon generally only reviews these fee disputes within 90 days of each charge.

Key takeaways

• Most FBA fee overcharges are not dramatic. They are a few cents or a dollar per unit, repeated on every order until someone notices.
• The usual cause is measurement: a bulging polybag, a loose flap, or a supplier’s carton dimensions sitting on your listing.
• Amazon uses the greater of the unit weight and the dimensional weight, so a box that is a little too big can cost more than a box that is a little too heavy.
• The fix has two steps: get the measurement corrected first, then claim the fees charged at the wrong size.
• The 90-day window means a quarterly fee review is often too late for the first charges.

Why FBA fee overcharges are so easy to miss

Nobody gets an email that says “this SKU now costs more to ship.” Amazon publishes its rate cards for everyone. It does not tell you that one particular product was remeasured last Tuesday and moved up a tier.

So the change hides inside your settlement reports. A seller with 40 SKUs and a few thousand orders a month sees thousands of fulfillment fee lines. One SKU jumping from one tier to the next looks like noise unless you track the fee per unit, per SKU, over time.

Here is the part that changes how we think about it. An overcharge is not a one-off cost. It is a recurring leak with a deadline. Every day it runs, you pay again, and every day older charges move closer to falling outside the dispute window. The longer you wait to look, the more you pay and the less you can recover.

What actually causes a wrong FBA fee

In our experience, almost every fulfillment fee overcharge comes back to one of four causes.

1. Packaging that measures bigger than it looks. Amazon says its fulfillment centers use sensors that capture the package edge to edge, including loose material like polybag flaps and handles. A product that measures neatly on your desk can scan bigger in the warehouse if the bag is loose or the box bulges.

2. Dimensional weight. Amazon uses whichever is greater: the weight on the scale or the dimensional weight worked out from the package size. In the US, Amazon calculates dimensional weight by multiplying length, width and height in inches and dividing by 139. A light product in a roomy box can end up billed as a heavier one.

3. The wrong dimensions from the start. Sometimes the dimensions on file came from the supplier’s outer carton or an old version of the packaging. Every unit is then charged as if it were the bigger package.

4. A remeasure that went the wrong way. Amazon remeasures products from time to time. Usually that helps, but a single bad scan of one damaged or overstuffed unit can move a SKU up a tier until someone challenges it.

How to spot an overcharge in 20 minutes

You do not need software to check your top sellers. Block 20 minutes and work through this list.

1. Pick your 10 best selling FBA SKUs. Overcharges on high volume products cost the most, so start there.
2. Measure one unit yourself. Measure it as the customer would receive it, with loose packaging pulled out to its full extent. Record the longest side as length, then width, then height, plus the weight.
3. Work out the size tier you expect. Use Amazon’s published size tier rules and the FBA Revenue Calculator for your marketplace. Write down the fee you expect per unit.
4. Check what Amazon has on file. In Seller Central, look at the dimensions, weight and fee shown for the SKU in your FBA inventory and the Fee Preview report.
5. Compare fees over time. In your transaction or settlement data, divide the fulfillment fee by units for the last week and for a month ago. A jump with no price or category change is a red flag.
6. Flag every SKU where Amazon’s size or fee is higher than yours. Those are your candidates.

A quick example (illustrative only, not a real seller): a skincare brand sells about 1,500 units a month of one serum. Its own measurements put the boxed bottle in a small standard tier. After a remeasure, Amazon’s record shows a slightly longer box, and the fulfillment fee rises by about 60 cents a unit. That is roughly $900 a month on one SKU, and nobody on the team noticed for six weeks because total fees only moved a little.

How to get the size corrected

Once you have a candidate, fix the measurement before you ask for money. A claim is much stronger once Amazon’s own records show the correct size.

1. Request a remeasurement. Amazon points sellers to the “Remeasure FBA products and confirm fees” tool, which you can find by typing “remeasure” into the Seller Central search bar. Amazon says it will find a sellable unit in a fulfillment center and remeasure it, typically within 10 days.
2. Only request remeasures you expect to change your fees. Amazon says that sending too many requests that do not change fees can slow down the ones that do.
3. Know the limits. Amazon says a product cannot be remeasured if it has already been remeasured twice in the past 60 days, if there are no available units in the fulfillment center, or if your account has hit its monthly request limit.
4. Fix the packaging if you were the cause. If the bag is loose or the box bulges, Amazon’s measurement will win. Amazon recommends uniform packaging, tight or vacuum sealed polybags and taped down flaps. Changing the packaging stops the leak on future units even if past charges cannot be recovered.

How to claim the overcharged fees

After Amazon confirms the smaller size, the fees you paid at the wrong size can be claimed. Amazon says it will reimburse FBA fees when it confirms they were charged using inaccurate weight or dimensions.

• Open a case through Seller Central Help under the FBA fee issues area (sellers often see it as fees charged in error). Menus change, so confirm the current path in Seller Central.
• Include the evidence: the FNSKU and ASIN, the remeasurement result or case ID, the dates the wrong fee applied, the order IDs if you have them, and the fee you were charged versus the fee at the corrected size.
• Watch the clock. Amazon generally reviews these fee disputes within 90 days of each charge. Charges older than that are usually gone, which is why catching the change early matters more than anything else.
• Keep it simple and factual. One SKU, one cause, the numbers and the proof. Clear cases tend to be resolved faster than long ones.

Common mistakes that cost sellers money

• Waiting for the quarterly review. By then, the first weeks of overcharges may already be outside the 90-day window.
• Claiming before the remeasure. Without a corrected measurement, the case usually comes down to your tape measure against Amazon’s sensor.
• Looking at total fees, not fee per unit. Total fees rise with sales. Fee per unit is what reveals a tier change.
• Blaming your own price change. Referral fees move with price. Separate price-driven changes from size-driven ones before you open a case.
• Fixing the claim but not the packaging. If the box still bulges, the next remeasure can push you right back up.

How BidVentor handles fee overcharges

We built Fee Sentry to do the 20-minute check above on every SKU, every time it scans, so you are not relying on someone remembering to look. It is now live. You connect your Amazon seller account once, and it reads your payments, reports and Amazon’s own fee estimates through the Selling Partner API.

Fee Sentry works out the fee per unit for each SKU from your settlements and compares it with what the SKU paid before and with Amazon’s fee estimate. When a fulfillment fee jumps, it checks whether Amazon changed the size tier or weight, shows what the change costs you each month, and drafts the case text with the remeasure steps when the size looks wrong. It also tracks the filing window for each claim. You stay in control: you review the evidence and file the case yourself in Seller Central.

Fees are only one place profit leaks out. Running out of stock is another, and BidVentor’s replenishment tools, including Stockout Guard, put a date and a dollar figure on each stockout risk. On the advertising side, the Amazon Ads Profit Machine cuts wasted spend, and its 4X ROAS guarantee applies to PPC only, terms apply. If you want to see how ad waste and stockouts connect, our guides on reducing wasted ad spend and choosing Amazon replenishment software go deeper.

You get one free analysis after you sign up, so you can check your own catalog before you change anything.

When a manual check is enough

If you sell a handful of FBA products with simple, rigid packaging and you check fees once a month, the manual method above is enough. Keep a small sheet with each SKU’s measured size, expected tier and expected fee, and compare it with Amazon’s numbers monthly. Move to an automated check when you have more SKUs than you can measure in an afternoon, when your packaging varies, or when you discover an overcharge only after the 90-day window has closed.

Frequently Asked Questions

How do I know if Amazon is overcharging my FBA fees?

Compare the fulfillment fee per unit each SKU pays now with what it paid a few weeks ago and with the fee you expect from your own measurements and Amazon’s size tier rules. A jump with no change in price or category usually points to a size or weight change.

How long do I have to dispute an FBA fee overcharge?

Amazon generally reviews fee disputes tied to weight or dimensions within 90 days of each charge. Amazon changes these windows from time to time, so confirm the current one in Seller Central before you file.

How do I request an Amazon FBA remeasurement?

Type “remeasure” into the Seller Central search bar and use the “Remeasure FBA products and confirm fees” tool. Amazon says it remeasures a sellable unit at a fulfillment center, typically within 10 days.

Will Amazon refund fees charged at the wrong size?

Amazon says it reimburses FBA fees when it confirms they were charged using inaccurate weight or dimensions. Its own measurement governs, so get the remeasurement confirmed first and then open a case with the dates and amounts.

Why did my FBA fee go up when my product did not change?

The most common reasons are a remeasure that recorded a bigger package, dimensional weight on a roomy box, or a new fee type on the SKU. Loose polybags and bulging boxes are frequent culprits because sensors measure edge to edge.

Sources and further reading

• Amazon Seller Forums: Importance of accurate product measurements, including how remeasurement requests and FBA fee reimbursements work.

Related guides

• Amazon replenishment software: how to choose one
• Reduce wasted ad spend on Amazon
• How to analyze Amazon reviews, step by step

About the reviewer

Adeel Imrani is the founder of BidVentor. He spent 14 years growing a $2M beauty brand on Amazon and has managed $30M+ in ad spend. Read more on his author page.

How we make this content

These guides are written by the BidVentor Editorial Team and reviewed by Adeel Imrani. Where we cite Amazon features or numbers, we link to Amazon’s own documentation. We update guides when Amazon’s tools or our guidance change, and we describe BidVentor’s features as they work today. See our methodology, or contact us with corrections.