What Will Happen If You Ship a USPS Package with Incorrect Dimensions?
The United States Postal Service (USPS) generally calculates postage based on the actual or dimensional weight of a package, whichever is higher. If you ship a package at a post office, a postal employee will weigh and measure it for you. When you buy postage online, however, you are responsible for providing accurate weight and size information. So, what happens if you ship a USPS package with incorrect dimensions?
The three dimensions of a rectangular package are length (always the longest dimension), height, and width. These dimensions are measured in inches and are used to determine the dimensional weight of a package, which reflects how much space the package occupies. To calculate dimensional weight, round each dimension up to the next whole inch, multiply the three dimensions, and then divide the result by 139 (the USPS volumetric divisor). Finally, round the result up to the next whole pound.
The USPS also uses the term “girth” when referring to maximum package size. Package girth is the distance around the thickest part of the sides that are not the length. For rectangular packages, girth equals the width multiplied by two plus the height multiplied by two. For cylindrical packages, girth is the circumference of the cylinder.
In the context of maximum size, USPS packages are measured by length and girth combined. The maximum size is 108 inches for domestic Priority Mail and Priority Mail Express packages and 130 inches for USPS Ground Advantage packages. USPS Ground Advantage packages measuring between 108 and 130 inches in length and girth combined are charged an oversize fee; packages that exceed 130 inches in length and girth combined are unmailable.
Now that we know why the USPS needs package dimensions (to calculate dimensional weight and postage, as well as determine if a package exceeds the maximum size limit), let’s figure out what happens if you submit incorrect dimensions when buying a shipping label online, either accidentally or on purpose.
The outcome depends on several factors:
- Whether the dimensions you entered were too small or large
- Whether the package exceeded the maximum dimensions
- How off the dimensions are
- When the discrepancy in the dimensions was flagged
- How you purchased and paid for the shipping label
If the discrepancy is small and the package does not approach the maximum size limit, it will likely not affect the price, and your package will probably be delivered without issue. The same applies when you overstate the dimensions, but the package is still within the maximum size limit. In such cases, you will likely overpay, but USPS will simply deliver the package without refunding the difference.
Understating the dimensions is another situation. If the discrepancy is flagged at the counter, you will have to pay a postage adjustment fee if your package is within the limit, or your package will be rejected if it exceeds the limit. However, if your package is accepted, that does not mean you’re in the clear.
The USPS uses the Automated Package Verification (APV) system to detect discrepancies between the stated and actual weight or measurements of packages during delivery. If your package is flagged for incorrect dimensions, there are four possible outcomes.
- If you purchased a shipping label through Click-N-Ship or an authorized third-party service with a card associated with your account, the postage adjustment may be charged to your account automatically.
- If the USPS cannot charge you automatically, the package may be delivered with postage due, meaning the recipient will have to pay the adjustment.
- The USPS may also return the package with an “insufficient postage” notice. In this case, you will have to reship the package with a new shipping label, correct measurements, and correct postage.
- If the package exceeds the maximum size limit, it will be returned as unmailable.
Generally, shipping a package with incorrect dimensions is not the end of the world, especially if the discrepancy is negligible. However, it’s better to avoid such situations.