Not a glitch. This was a failure to execute. Amazon was getting ready to allow sellers to link their own USPS accounts to Amazon about the same time. Probably just held back to accommodate their engineers and/or bots. That’s not a glitch but a business decission.
Screwing over sellers = working as designed.
A common UPS surcharge is address correction. And it is a hefty surcharge $25.25 per package plus fuel surcharge. I have no experience with how Amazon currently reports this charge.
Just a follow up …
Originally from our email from Amazon, all of our adjustment were to be done between Sept 7 and Sept 10. The final adjustments hit on Sept 12. All of the adjustments total matched the email’s stated total … so no surprises. All of the adjustment dates were between Jan 18 to Feb 18 as we expected and had noted on our excel tracking sheet.
Sales were at a trickle during the adjustments, but, to be fair, this time of the year (September) is normally a slow period for us … so it is a little hard for us to say if Amazon throttled sales while doing the adjustments.
Now …quietly awaiting the start of Glitchmas …
My last adjustment showed up on 9/11, for a 1/20 label that should have been $5.52 instead of what amazon charged us as $5.15.
I made the following post in another thread on Jan 20th:
Well after almost 8 months, both questions were answered. USPS did came asking for more money (why waited so long?), and Amazon didn’t take the responsibility of their fault. 
I suspect that this 093026 NSFE reply - one or another version of which that long-time seller has been posting, for the last 10 days or so, to more than a few of the plethora of “Shipping Overcharge Adjustments” threads now-clogging the Creeping Horror - likely strikes quite close to the mark:
Not sure we believe this part. So Amazon makes 9% to 19% off of USPS? Nope.
It was clear to us that Amazon didn’t execute the Jan 2026 price increase until 30 days later and, when they did, the prices became the same as other providers like PirateShip. Then 8 months later, charged the sellers for the difference of the miss charged labels and tried to pass it off as a USPS thing.
My belief is they must make somewhere in this range to cover A-Z protected claims. I don’t believe they do this out of kindness to 3p sellers.
As a slightly different take on our own “adjustments”, we don’t use Amazon shipping, instead use Veeqo. I haven’t seen any adjustments on Veeqo of our outbound shipping, somehow they get it right the first time (despite being part of Amazon).
What I have seen is the for EVERY return (which come by UPS of course), there is eventually an adjustment. Half of those are $.01. The other half range from $.11 to $.88; over the course of 2026, we’re out $1.75 total. That’s it.
P.S. As far as what has been discussed above, this is likely intended malfeasance (or at best gross incompetence) and not honest business. Part of the Amazon Marketplace culture. Just my two cents.
gotta agree with @svbooks
every shipping adjustment we get is for returns. Every single return. sometimes as little as $0.04 the most luckily was $8.48 because they shipped the item in a 10x12x4 box and it was originally shipped in a 6 x 10 padded envelope.
