USPS uses an Automated Package Verification (APV) system to verify that all shipments match the details and qualify for the service selected on the label. Prior to APV, packages with postage discrepancies were either returned to the sender to be corrected or delivered to the recipient to pay the postage due. That process could delay shipments and create a negative recipient experience, especially when they had to pay for extra, unexpected postage. With APV, the USPS instead delivers the package but then issues cost adjustments back to your postal account balance. This process means the adjustment is automatically deducted from your prepay balance within XPS Ship. Below are some helpful tips on how to calculate the correct postage the first time to avoid adjustments and make for a more efficient shipping process with USPS.
When Does a Postage Difference Occur?
Generally, a postage difference occurs when the package characteristics (e.g., weight, dimensions, zone, etc.) used for label creation do not match measurements of the actual package mailed (as captured by USPS processing equipment). Most commonly, one of these reasons result in a different mail class or rating category:
Incorrect weight on label resulting in a price difference due to a different rating or exceeding limitations for the class chosen.
Incorrect dimensions versus those of the actual package shipped.
Incorrect service or packaging entered for label creation versus actual service/packaging material used (e.g., Ground Advantage labels cannot be used on Priority Mail or Priority Mail Express packaging).
APV verifies that the following details match the shipping label:
Weight
Dimension
Mail Class
Packaging
Origin Zip Code
Destination Zip Code
Postage Paid
How to Calculate Postage Correctly
Weigh Your Item and Round Up
USPS rounds up to either the next pound (lb) or ounce (oz). For example, if your package weighs 3 lbs 5 oz, it would be charged at the 4 lb rate. If you are shipping an item using Ground Advantage that weighs 7.3 oz, the item must be charged at the 8 oz rate. As long as you are entering the actual weight when creating the label (e.g., 3 lbs 5 oz), the system automatically charges for the correct rounded-up weight. The use of a postage scale can help ensure accurate weights are being entered.
You can also visit the Help Center Article: What scales are supported by XPS Ship?
Select the Right Mail Class
Ground Advantage cannot be shipped in USPS Priority packaging. For more details visit the Help Center Articles: Shipment Size and Weight Restrictions and USPS Cubic Rates.
Measure Your Package
Measure the length, width and height of the package. Dimensional (DIM) weight may also apply to your packaging. DIM weight is determined by multiplying a package's length, width and height and then applying a volumetric divisor. DIM weight = Length x Width x Height ÷ 166. As long as you are entering the actual dimensions when creating the label, the system automatically charges for the correct DIM weight.
For more details visit the Help Center Articles: What is Dimensional Weight? and USPS Cubic Rates.
Label Your Package Correctly
Make sure that the label you are using matches the packaging. For example, if you are using a Flat Rate Box, you should also use a Flat Rate label. Anything shipped in Priority Mail packaging requires a Priority Mail label. Ground Advantage service would require you to use your own packaging.
For more details visit the Help Center Article: USPS Priority Packaging: Flat Rate, Regional and Non-Flat Rate Boxes.
Double-Check the Zone
Zones are calculated using ZIP codes and vary based on the distance from the origin of a shipment to its destination. Verify that the origin address (or "Sender") is up to date before printing the label. If the sender's address is incorrect, that ZIP code can result in the incorrect zone being used to calculate the postage.
If you need to change the sender address, visit the Help Center Article: How do I change my default sender address?
How to Dispute a USPS Shipment Adjustment
If you feel you were charged in error, you can dispute the charge with USPS. For the steps to dispute the charge, visit the Help Center Article: How to Dispute a USPS Shipment Adjustment.