Find direct answers to common questions about using USPS-issued Forever stamps. Complex questions have their own detailed pages so dimensions, weight, destination, postage math, and exceptions are not compressed into a one-line answer.
How many Forever stamps for a 9×12 envelope?
A 9×12 envelope is normally a large envelope. Check the current 1-ounce postage math and the rigidity and thickness rules that can change its mail class.
How many Forever stamps to Canada?
Compare one Global Forever stamp with combinations of ordinary domestic Forever stamps and see when additional international postage is required.
Can I use two Forever stamps?
Yes, stamps can be combined. Calculate the actual requirement first to avoid overpayment or a postage shortage.
Can you use Forever stamps on postcards?
An ordinary Forever stamp can cover a domestic postcard, but the postcard-rate stamp is usually a closer value.
Start with the right guide
- How Forever stamps work
- Forever stamp price and value
- How many Forever stamps do I need?
- Forever stamps for international mail
- Browse stamp categories
How we check answers
Rate-sensitive answers state the effective date and link to the relevant USPS source. Always verify the finished mailpiece because weight, size, shape, rigidity, contents, and destination can change the required service or postage.
Learn more about our sourcing and editorial process on About SaleForeverStamps.