When to Use First-Class Forever Stamps for Everyday Mail
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A first class Forever stamp costs $0.82 right now (as of August 2026 — check usps.com before you buy a big batch, since USPS adjusts rates every so often). It never expires, and it always covers a standard one-ounce letter mailed anywhere in the U.S., even if postage climbs to a dollar next year. That's the whole appeal. The tricky part isn't buying them. It's knowing when one stamp does the job and when it quietly doesn't.
Most household mail is fine with a single stamp. A birthday card, a bill payment, a signed permission slip for school. But the moment you tuck a second sheet inside, or slide in a gift card, the math changes. This guide walks through the everyday pieces you actually mail and tells you exactly how many stamps each one needs.
When One Stamp Is Enough
One first class Forever stamp covers any standard rectangular envelope up to one ounce mailed within the United States. That's roughly a #10 business envelope holding three sheets of regular paper, or a greeting card with a short handwritten note. If it bends easily and weighs under an ounce, one stamp carries it.
Here's a rough weight cheat sheet for the mail that piles up on most kitchen counters:
| What you're mailing | Approx. weight | Stamps needed |
|---|---|---|
| Single-sheet letter in a #10 envelope | ~0.3 oz | 1 |
| Greeting card, no insert | ~0.5 oz | 1 |
| Bill payment (check + return slip) | ~0.5 oz | 1 |
| Greeting card + folded photo or gift card | ~1.1 oz | 2 (or 1 + extra ounce postage) |
| Wedding invite with RSVP card and liner | ~1.5–2 oz | usually 2, sometimes square-envelope surcharge |
The last two rows trip people up constantly. A card that felt light in your hand can cross the one-ounce line the second you add something. When in doubt, a kitchen scale saves you a returned envelope.
When One Stamp Isn't Enough
Cross one ounce and USPS charges roughly $0.24 for each additional ounce (verify the current per-ounce figure on usps.com — it shifts with rate changes). So a two-ounce letter runs about $1.06, not two full Forever stamps, though sticking on a second Forever stamp works too and only "overpays" by a few cents.
Two situations catch people off guard. Square envelopes — think fancy invitations — get a non-machinable surcharge because they can't run through automated sorters. Same goes for rigid or lumpy envelopes, like one holding a key or a bulky pin. If you can't easily bend it, budget for extra.
The Forever stamp handles the weight jump gracefully. Buy the extra postage as a single make-up stamp from the post office, or just add another Forever stamp and accept the small overage. For anyone mailing dozens of pieces at odd weights, understanding how forever stamps work against the current rate table is worth ten minutes before you seal everything.
Old Stamps: Still Good?
Yes. A Forever stamp you bought in 2009 at 42¢ is worth a full first-class letter today, no matter what you paid. That's the promise baked into the name — "Forever Means Forever," as Stamps Forever puts it. You never owe the difference on a genuine Forever stamp.
Denomination stamps are a different animal. A 37¢ stamp printed before Forever stamps existed (the first Forever stamp shipped April 12, 2007, per USPS) is still valid postage — but only for its printed value. Stick a 37¢ stamp on a letter and you owe 45¢ more to hit the current $0.82 rate. Combine leftovers to reach the total: a 55¢ plus a 27¢ works, or a couple of low-value stamps plus a small make-up stamp. Dig the old ones out of the junk drawer; they're money, just not always a whole letter's worth.
If you've inherited a shoebox of mixed stamps and aren't sure what's genuine, our guide to unused forever stamps covers how to spot real ones before you rely on them at the mailbox.
Where Forever Stamps Fall Short
International mail. This is the big one nobody warns you about. A first class Forever stamp does not pay for a letter to Canada, Mexico, or anywhere overseas. International first-class letters need Global Forever stamps or the correct international rate — a domestic Forever stamp on a postcard to London gets it returned or delayed.
Packages are out too. Forever stamps cover letters and cards, not boxes. For anything in a padded mailer or box, you're into package rates, and for volume mailing, USPS Click-N-Ship or a service like Stamps.com usually beats sticking on strips of stamps by hand.
One more honest limit: Forever stamps are a fixed one-ounce tool. If most of your mail is heavy, oversized, or headed abroad, they're the wrong default — buy them for the letters and cards, and price the rest separately.
Where to Buy Them
You've got real options, and price barely moves at face value — the difference is convenience and, for older or discounted stock, authenticity. The USPS Official Store, any Post Office counter, Walmart, Target, Costco, and Amazon all carry current Forever stamps. Grocery-store customer service desks often stock a book or two.
Bulk buyers should watch two things: counterfeit risk on secondary marketplaces, and the condition of "discount" stamps. We source our unused stamps from closed businesses and inspect every one for authenticity and flawless, unbent condition — that inspection step is exactly what protects you from the fakes that float around third-party resellers. If you're stocking up on wholesale first class stamps for a small business or a season of invitations, buy from a source that guarantees the stamps are real and refundable. For readers weighing whether older or bulk stock still holds full value, our do forever stamps expire page settles it plainly.
FAQ
Can I still use first-class forever stamps?
Yes. Genuine Forever stamps never expire and always cover a standard one-ounce domestic letter, no matter the year you bought them or the price you paid.
How much does a first-class Forever stamp cost now?
A first class Forever stamp costs $0.82 as of August 2026. USPS adjusts rates periodically, so confirm the current price on usps.com before buying in bulk.
Are 10 year old forever stamps still good?
Absolutely. A Forever stamp from 2016 pays for a full first-class letter today at no extra charge — age never reduces its value or validity.
What's the difference between first-class stamps and forever stamps?
Today's first-class one-ounce stamps sold by USPS are Forever stamps. Older denomination stamps (like a 37¢ stamp) are only worth their printed value, so you must add postage.
Sorting your mail by weight before you stamp it takes thirty seconds and prevents most returned envelopes. Keep a book of genuine Forever stamps on hand for cards and letters, a scale nearby for anything with an insert, and separate international pieces from the domestic pile. When you're ready to restock, Mailboxes of Flushing ships inspected, authentic Forever stamps within 24 hours — with a 7-day refund window if any stamp doesn't meet your expectations.