Reviewed September 12, 2026. A “Priority Mail stamp” is postage intended to help pay for Priority Mail service. It does not create one universal price: the required total depends on the service option and mailpiece.
Two main pricing paths
Flat Rate packaging
Eligible USPS Flat Rate packaging uses the current published price for that specific package and service, subject to the applicable rules.
Weight-and-zone or dimensional pricing
Other Priority Mail pieces can be priced by origin, destination zone, weight, dimensions and surcharges. The claim that every one-pound Zone 1–4 package has one permanent base amount is not a sufficient current rule.
How a denominated stamp works
A stamp with a printed dollar amount contributes that amount toward the current Priority Mail total. If the service price is higher, add valid postage. A commemorative image does not change the denomination.
Calculation steps
- Select Priority Mail and the packaging type.
- Enter mailing date, origin and destination.
- Measure and weigh the packed item.
- Use the USPS postage calculator.
- Subtract the value of stamps already applied and add the remainder.
Counter rule for stamp-paid packages
USPS requires a mailpiece paid only with stamps and weighing more than 10 ounces or thicker than one-half inch to be presented to a postal employee at a retail counter. Do not place such a piece in an unattended collection box.
Current service rules are available from USPS Priority Mail.