Got this email tonight. I've had no returns in 2026 so that's not a reason. My return address isn't incorrect because It has not changed since the day I signed up on Amazon so that's not a reason. I have 1 package type I use when I ship through Amazon's buy shipping it's a flat 7" x 5" mailer that weighs 4 oz. The dimensions and weight never change so that's not a reason.
The only reason I can come up with is Amazon, and this happens frequently, is always behind on getting their buy shipping rates synced up with USPS rates and there were a bunch of small shortages on the cost that added up during this time frame, due to Amazons fault for not getting things set up right on time. These types of adjustments Amazon should have to eat as it is their system printing labels with the incorrect amounts. Granted it's overall a small amount for that 3 month period, but sellers should not be responsible for Amazons lack of preparedness when they have a very long time in advance to bake in the correct rates and on go day they can just turn them on in an instant, but I have noticed sometimes Amazon goes weeks before they catch up on new rates. Do better Amazon__________________________________________________________________________________________
Hello,
USPS assessed shipping correction charges totaling -19.92 on Fulfilled by Merchant labels you purchased on Buy Shipping between 01_01_2026 and 03_31_2026. You'll be charged for these corrections between 09_07_2026 and 09_10_2026.
USPS applies these charges when the dimensions or weight of a package don't match the label, or when your return address is incorrect or invalid. These charges may not appear in the same settlement period as the original shipment.
View your charges: Go to your Payments Dashboard. In Transaction View, filter by Shipping services purchased through Amazon, then search for "Adjustment" in the Product Details column.
Avoid future correction charges: Confirm that your products' dimensions, weight, and return address are listed correctly in Seller Central.
For more information, go to Carrier shipping correction charges.
The Amazon Services team