Amazon is deducting retroactive shipping adjustments without providing proof — other sellers need to review their accounts

I want to make other Amazon sellers aware of a serious issue we are currently experiencing with Amazon Buy Shipping and retroactive USPS shipping adjustments.

Amazon has been deducting money from our seller account for shipments that were completed months ago, claiming that USPS later determined that additional postage was owed.

The problem is simple: Amazon is taking the money, but so far has not provided us with actual USPS documentation proving that USPS requested these specific adjustments.

We have repeatedly asked Amazon to provide, for each charge:

The Order ID and USPS tracking number.

The original postage amount.

The amount of the adjustment.

The original package weight and dimensions.

The weight and dimensions allegedly measured by USPS.

The specific reason for the adjustment.

The date USPS supposedly reported the discrepancy.

The actual USPS APV, carrier record, transaction record, or other documentation proving that USPS assessed the charge.

Instead, sellers are often given generic explanations about how shipping adjustments work.

That is not evidence.

If Amazon removes money from a seller's account and claims that the carrier requested the charge, Amazon should be able to produce documentation from that carrier supporting the deduction.

These are not small amounts. When adjustments from multiple shipments are suddenly deducted months later, they can add up to hundreds or even thousands of dollars, directly affecting a seller's cash flow and ability to operate.

What is especially concerning is the lack of transparency.

We purchase shipping through Amazon Buy Shipping based on the rate, weight, and dimensions accepted by the system at the time of shipment. Months later, Amazon can debit the account with a shipping adjustment, while the seller is left trying to prove that the charge is incorrect without being given the underlying evidence that supposedly created the charge in the first place.

How is a seller supposed to dispute an adjustment when Amazon will not provide the carrier documentation behind it?

Amazon should not be allowed to simply say, “USPS made the adjustment,” deduct the money, and consider the matter resolved.

We are asking Amazon to provide full documentation for every disputed adjustment. If Amazon cannot demonstrate that USPS actually assessed a particular charge, then that money should be returned to the seller.

I strongly encourage every seller using Amazon Buy Shipping to review their transaction history, shipping adjustments, and older USPS shipments carefully.

Check whether Amazon has charged you retroactively for shipments from previous months.

If this has happened to you as well, please share your experience here.

Sellers deserve transparency, documentation, and accountability when money is removed from their accounts.

A deduction should never be considered justified simply because Amazon says it is.

Amazon: show us the USPS evidence behind these charges.