Starting on April 3, 2022, USPS now imposes package surcharges known as "Non-Standard Package Fees" on most of their domestic shipping services when packages exceed certain dimensions.
The USPS services subject to these surcharges are: First Class Package Service®, Priority Mail®, Priority Mail Express®, and Parcel Select Ground®.
Media Mail® shipments will not be subject to any non-standard package fees.
The new "Non-standard" USPS surcharges
Here are the new USPS surcharges, and the situations when they apply:
$4 if any length of your package exceeds 22 inches but is less than 30 inches*
$15 if any length of your package exceeds 30 inches*
$15 for packages greater than 2 cubic feet in volume
$1.50 for missing or incorrect dimensions that result in any of the above non-standard surcharges
*Note that neither the 22" or 30" dimension-based surcharges apply to First Class Package Service, because you can't buy First Class Package labels if a single dimension on your package exceeds 22". First Class Package shipments can be greater than 2 cubic feet in volume, though, and those shipments could be subject to the $15 surcharge 😅