You shipped a package at the post office for $12. A week later, you get an email: the carrier has billed your eBay or Pirate Ship account an additional $25 because the package was "remeasured" at the carrier's hub and was larger than what you declared.
This is increasingly common. Here's what's happening, why it's legal, and what you can do about it.
The mechanics
Every major carrier — UPS, FedEx, USPS, DHL — runs packages through automated dimensional scanners at their distribution centers. The scanners capture length, width, height, and sometimes weight, and feed those values back into the billing system. If the scanned dimensions or weight exceed what was declared on the shipping label, the system generates an adjustment.
The adjustment can be:
- Dimensional weight correction: the package was bigger than declared, so DIM weight is recalculated and you owe the difference
- Oversize surcharge: the package crossed the 130-inch threshold at scan, so the oversize fee applies
- Weight adjustment: actual weight was higher than declared
- Address correction: the address required correction or the package required redelivery
These adjustments are billed back to whoever paid for the label. If you used a service like Pirate Ship, eBay Labels, or ShipStation, the adjustment is passed to your account. If you used a UPS or FedEx account directly, it appears on your weekly invoice.
Why this is legal
When you print a shipping label, you're declaring dimensions and weight to the carrier. The carrier's terms of service say they may verify and re-rate. By using the service, you've agreed to this.
The carriers argue this is necessary because some shippers systematically under-declare to save money. The scanners catch this and recover the lost revenue.
In practice, the scanners are not infallible. Studies have shown that automated dimensional scanners can be off by an inch or more, especially for soft-edged packages, packages with handles, or packages oriented unusually on the belt. But the carrier's reading is the default.
What you can dispute
Adjustments can absolutely be challenged, and they're often overturned if you make the case.
Photo evidence. Photograph the package next to a tape measure before shipping. Include all dimensions clearly. If the carrier claims your 14-inch package was 17 inches, your photo wins.
Original packaging dimensions. If you used a standard sized box (e.g., USPS Flat Rate, Amazon-branded, Uline), the box's known dimensions are evidence.
Weight verification. Photograph the package on a scale showing weight. If the carrier claims 12 lb and you have a photo of 9 lb on a calibrated scale, you have a case.
Dispute mechanisms differ by service:
- UPS: contact billing dispute through ups.com/billing
- FedEx: fedex.com/disputes
- Pirate Ship: support ticket; they're aggressive about disputing on your behalf
- eBay Labels: limited dispute options; eBay typically absorbs small adjustments
How to prevent adjustments in the first place
Measure after packing. A box that measures 12 × 10 × 6 empty might measure 12.5 × 10.5 × 6.5 after you've packed it and the seams have bulged. Carriers measure as presented.
Round up when declaring. If you measure 12.3 inches, declare 13. Half an inch of rounding-up costs you cents on the label; getting it wrong costs you the adjustment plus the dispute fight.
Weigh after packing. Same principle. Include the weight of the box and packing material.
Use a calibrated scale. A bathroom scale isn't accurate enough for packages under 5 pounds. A $20 shipping scale pays for itself in one avoided adjustment.
Avoid pushing thresholds. If your package is 129 inches length plus girth, even minor measurement variance pushes you over the 130-inch surcharge line. Aim for 5-10 inches of margin below any threshold that triggers fees.
If you get hit anyway
Dispute small adjustments routinely. Carriers expect a certain percentage to be challenged; if you're a regular customer, they'll often credit them back without extensive review.
Use the girth calculator to verify your declared dimensions match the formula, and the volumetric weight calculator to verify your weight basis. Print these calculations and keep them with your shipping records for 90 days — long enough to cover most adjustment windows.