In 2006, the US Postal Service applied for permission to issue a stamp similar to non-denominated stamps in the US, termed the "forever stamp", for first-class postage.
On March 26, 2007, the US Postal service unveiled the first such stamp, which went on sale April 12, 2007, for 41 cents (US$0.41), the so-called "Liberty Bell" stamp, which is marked "USA FIRST-CLASS FOREVER".
These stamps are always sold at the current first-class postage rate. They are always valid for the full first-class postage regardless of any rate increases since the stamps' purchase (unused "forever" stamps purchased in April 2007 therefore are valid for the full 44 cent first-class postage rate, despite having been purchased for 41 cents).
Customers can use Forever Stamps for international mail, but since all international prices are higher than domestic prices, customers will need to attach additional postage. The value of the Forever Stamp is the domestic First-Class Mail letter price in effect on the day of use.
If you need stamps, you can buy stamps online at Stamps.com