Yes. Valid Forever stamps can be used to pay Priority Mail postage. Each ordinary Forever stamp contributes its current domestic one-ounce letter value, but the item is still priced as Priority Mail—not as a letter. You must affix enough total postage and follow Priority Mail packaging, marking and deposit rules.
How to Calculate the Number of Forever Stamps
Find the correct Priority Mail retail price, divide it by the current ordinary Forever value, then round up to the next whole stamp. As checked September 1, 2026, one ordinary Forever stamp is worth $0.82.
Number of stamps = Priority Mail price ÷ $0.82, rounded up.
Because whole Forever stamps can exceed the exact price, a combination of Forever stamps and smaller-denomination postage may cost less.
Priority Mail Flat Rate Envelope Example
The current retail price of a standard Priority Mail Flat Rate Envelope is $12.90. Sixteen ordinary Forever stamps provide $13.12, so they cover the price but overpay by $0.22. Fifteen provide only $12.30 and are insufficient. Prices change, so verify the amount on the mailing date.
| Step | What to check |
|---|---|
| 1. Choose packaging | Flat Rate packaging uses its stated price; other packaging may be priced by weight, dimensions and zone |
| 2. Get the retail price | Use the USPS calculator or ask at a Post Office |
| 3. Add postage values | Count each ordinary Forever stamp at the current ordinary Forever value |
| 4. Prepare the item | Use the required Priority Mail packaging or markings and include a return address |
| 5. Deposit correctly | Take stamp-paid pieces over the unattended-deposit limit to a retail counter |
Counter and Deposit Rule
A Priority Mail piece bearing only postage stamps that weighs more than 10 ounces or measures more than one-half inch thick cannot go into a collection box, lobby drop, customer mailbox or other unattended location. Present it to a USPS employee at a retail counter. A Priority Mail parcel commonly exceeds one of those limits, so counter acceptance is the safest route.
Forever Stamps Do Not Turn the Item Into Letter Mail
The payment method does not set the mail class. If you choose Priority Mail, the full Priority Mail price and preparation rules apply. Do not calculate the amount from First-Class Mail letter weight increments. For general combinations, see using multiple Forever stamps.
Frequently Asked Questions
How many Forever stamps do I need for Priority Mail?
There is no single number. Divide the current price for the exact Priority Mail package, zone and service by the current ordinary Forever value, then round up. Smaller denominations can reduce overpayment.
Can I use Forever stamps on a Priority Mail Flat Rate Envelope?
Yes. At the September 1, 2026 retail price, a standard $12.90 Flat Rate Envelope would require 16 ordinary $0.82 Forever stamps if no other denominations are used.
Can I put a stamp-paid Priority Mail package in a mailbox?
Only when it meets all deposit rules. If it bears only stamps and is over 10 ounces or over one-half inch thick, it must be handed to a USPS retail employee.
Do Forever stamps include Priority Mail tracking?
The stamps are only postage payment. Priority Mail service includes its applicable tracking features, but the package still needs correct Priority Mail preparation and acceptance. A retail counter can produce the appropriate transaction record.
Sources: USPS DMM 124, USPS DMM 126, and USPS Notice 123. Rules and prices checked September 1, 2026.