Usually, shipping costs increase as package weight increases. However, some USPS Ground Advantage shipments can currently cost less at a higher weight than at a lower weight, even when the package dimensions and other shipment details are the same.
We know that sounds backward! Here's what's happening and what you need to know when buying your labels.
Why can a heavier package have a cheaper USPS rate?
Beginning in June 2026, additional USPS discounts began affecting certain Ground Advantage rates that qualify for Below Commercial Pricing.
These discounts apply only to specific rate cells, rather than evenly across every Ground Advantage weight and zone combination. As a result, a discounted rate at a higher weight can occasionally be lower than the rate available for a lighter package traveling to the same destination.
For example, you may find that a Ground Advantage package weighing 3 or 4 pounds receives a lower rate than the same-size package weighing 2 or 3 pounds.
The discounts have changed periodically since June 2026, so the specific weight and zone combinations affected may also change over time.
Does this affect all USPS shipments?
No. This unusual pricing is limited to certain USPS Ground Advantage shipments and doesn't apply to other USPS services such as Priority Mail, Media Mail, or international services.
Because the affected rates can change, the best way to see the current price for a particular shipment is to enter its actual details into our Rates Calculator.
Should I enter a higher weight to get a cheaper rate?
No. Always enter your package's actual weight and dimensions when purchasing a shipping label. Even if you notice that a higher weight currently receives a lower Ground Advantage rate, the shipment information on your label should accurately describe the package you're sending.
USPS may verify a package's weight and dimensions as it moves through its network. If the information USPS records differs from the information used to purchase the label, you may receive a Carrier Adjustment.
Why did I receive a Carrier Adjustment when the lower weight costs more?
We know this can be especially confusing. Because of the way these discounts affect certain Ground Advantage rates, an adjustment based on your package's verified shipment details can occasionally result in a higher charge even when USPS records a lower weight. That can look like an error when you're accustomed to heavier packages costing more.
If you receive a Carrier Adjustment that doesn't make sense, reach out to our Support crew. We'll be happy to take a closer look at the adjustment and help you determine what happened.
Why is USPS pricing these shipments this way?
We aren't sure!
USPS determines its own rates and discount structures. We agree that seeing a heavier package ship for less can feel a little upside-down 🙃
For now, we recommend entering your shipment's actual weight and dimensions and using our Rates Calculator to see the current USPS rates available for your package.
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