Unused Forever stamps never lose their value#
Forever stamps never expire: an unused Forever stamp is always worth the current one-ounce First-Class letter price, which is $0.82 as of July 12, 2026, whatever you paid for it. USPS puts it plainly on its stamp basics page (opens in new tab): "U.S. postage never expires; you can use existing stamps indefinitely."
That goes for older stamps too. USPS says "all postage stamps issued by the United States since 1860 are valid for postage," and a stamp with a price printed on it keeps that value. A 29-cent stamp from 1991, when 29 cents mailed a letter, still counts as 29 cents of postage; you just add stamps to reach today's price. (The stamp price history shows what a letter cost in every year since 1885.)
What is your stamp worth? Read what it says#
The Forever rule also covers USPS's other Forever-type stamps, which name what they pay for instead of printing a price. Additional Ounce, Two Ounce, Non-Machineable Surcharge, Postcard and Global Forever stamps are each always worth the current price for that category, whatever you paid (USPS Domestic Mail Manual 604 (opens in new tab)). A stamp with no price printed on it is not automatically one of these: some older ones, like the "G" stamp, carry a fixed value set when they were issued.
What each kind of stamp is worth
What the stamp says | What it's worth | What to do with it |
|---|---|---|
Forever | The 1 oz letter price, $0.82 | One pays for a standard letter up to 1 oz |
A printed price, such as 37¢ | Exactly that amount, for good | Add stamps until the total reaches your letter's price |
Additional Ounce | The extra-ounce price, $0.29 | Add one for each ounce over the first |
Two Ounce | The 2 oz letter price, $1.11 | One pays for a letter up to 2 oz |
Non-Machineable Surcharge | The 1 oz price plus the surcharge, $1.31 | One pays for a square, rigid or lumpy letter up to 1 oz |
Global Forever (round) | The 1 oz international letter price, $1.75 | One pays for a 1 oz letter or a postcard to any country |
Postcard | The postcard price, $0.65 | Use it on a postcard; a letter needs more |
No price and none of these words | The fixed value it was issued at | Look it up in USPS's guide (below) or ask at a Post Office |
If a stamp has no price printed on it and no word such as Forever, Additional Ounce or Postcard, look it up in USPS's illustrated guide to nondenominated stamps (opens in new tab) rather than guessing from the year: some were issued before the rate they carry took effect. If a stamp is damaged and you can't tell its value, ask at a Post Office before relying on it.
Charity stamps (semipostals, such as Breast Cancer Research) work differently. Each is worth the one-ounce letter price on the day it was bought, not today's price, so one bought before a price increase needs extra postage.
USPS counts every stamp at face value only, however rare. If you think one might be worth more to a collector, USPS recommends asking a stamp dealer.
How much weight does one Forever stamp cover?#
One ounce. USPS's rule of thumb is that one Forever stamp mails about four sheets of printer paper in a business-size envelope (USPS letter instructions (opens in new tab)). A Forever stamp covers the first ounce only, however long ago you bought it; "Forever" describes its value, not its weight.
Each ounce over the first takes one Additional Ounce stamp, up to 3.5 oz for a letter. A square, rigid or lumpy letter up to 1 oz takes one Non-Machineable Surcharge stamp ($1.31) instead of a Forever stamp. The letter-cost guide shows how many stamps a heavier or larger letter needs, and the letter size and shape rules explain what counts as square, rigid or too big for a letter.
How to use old stamps with a printed price#
- Add up the printed values until you reach your letter's price. USPS lets you use any combination of stamps that adds up to the postage. For a standard 1 oz letter at $0.82, three 29-cent stamps make 87 cents, which covers it. A 44-cent and a 37-cent stamp make 81 cents, one cent short.
- Close any gap with low-value stamps. USPS sells 1-cent and 3-cent stamps, which its stamp basics page says are commonly used to top up older stamps. One 1-cent stamp turns that 81-cent pair into 82 cents.
- Stick them firmly in the upper-right corner of the address side. That is where USPS requires postage (the envelope addressing guide shows the full layout). Don't overlap them or cover the address: USPS may not count a stamp that is partly covered.
When the price changes, redo the sum. Your printed-price stamps keep their value; the target moves.
If you come up short, USPS delivers the letter only if your recipient pays the difference. If they won't, a letter with a return address comes back to you marked "Returned for Additional Postage." A short-paid square or rigid letter comes straight back to you (DMM 604, section 8 (opens in new tab)). Either way, you can add the missing postage to the same envelope and mail it again.
Which stamps can't you use?#
- Used stamps. A stamp that has already carried mail cannot be used again, even if it was never canceled. An unused stamp already stuck to an envelope you never mailed can still go out on that envelope. Don't cut it off and tape it to a new one: tape stops the stamp from being canceled, and USPS won't accept it.
- Damaged stamps. USPS won't accept a mutilated or defaced stamp, though a minor tear at a corner is fine.
- Stamps marked "Presorted." These are for businesses that hold a USPS mailing permit, not for personal letters.
- Stamps from other countries. They aren't valid on mail sent from the US.
Can you use Forever stamps abroad or on a package?#
On mail to another country. A domestic Forever stamp still counts only at the US letter price on international mail, and a 1 oz international letter costs $1.75 as of July 12, 2026. Use one Global Forever stamp, or add stamps to reach that price: two Forever stamps make $1.64, which is 11 cents short (International Mail Manual 152 (opens in new tab)).
Packages. Forever stamps are valid postage on a package, at 82 cents each, but a package needs many of them. A package paid only with stamps that weighs more than 10 ounces or is thicker than half an inch has to be handed to a Post Office employee rather than dropped in a mailbox (Postal Bulletin 22530 (opens in new tab)).
Should you stock up on Forever stamps before a price increase?#
If you will use them, yes. A Forever stamp you buy today still pays for a standard 1 oz letter after any future price change, because its value is always the current price, not the price you paid.
Stamps with a printed price and charity stamps don't keep pace, so if you stock up, buy Forever stamps. The only cost of buying ahead is cash sitting in a drawer until you use them.