Three. A standard 1 oz letter or postcard leaving the United States is priced by USPS at $1.75, and it says so with the Global Forever stamp built for exactly that job. But USPS also allows a shortcut most senders never hear about: any combination of stamps that adds up to the same amount. Two ordinary domestic Forever stamps at $0.82 each only reach $1.64, eleven cents short of the mark. A third one clears it, at $2.46 against the $1.75 owed. Read from usps.com on 2026-09-01.
Three ordinary Forever stamps clear an international letter. Two do not.
USPS's own page on mailing letters and postcards abroad puts the rule in one line, right after naming the Global Forever stamp price:
“You can also use any other combination of stamps that adds up to $1.75.”
USPS, International Mail: Letters and Postcards, usps.com, read 2026-09-01.
| Stamps used | Total value | Against the $1.75 price |
|---|---|---|
| 1 Global Forever stamp | $1.75 | Exact, built for this |
| 2 domestic Forever stamps | $1.64 | Short by $0.11 — not enough |
| 3 domestic Forever stamps | $2.46 | Over by $0.71 — clears it |
There is no domestic stamp count that lands on $1.75 exactly, because $0.82 is not a divisor of it. Two stamps undershoot, three overshoot, and nothing in between is sold in a single denomination. A letter mailed with two domestic Forever stamps and no more is short-paid, and USPS treats a short-paid letter as postage due rather than simply letting it through.
The domestic Forever stamp and the Global Forever stamp are priced on separate schedules, one for mail that stays inside the country and one for mail that leaves it, and nothing ties the two together. USPS's Notice 123 price list sets the domestic 1 oz letter at $0.82, checked live on 2026-09-01. Its international letters page sets the international 1 oz price at $1.75, checked the same day. A sender reaching for the drawer of ordinary stamps is combining a domestic price against an international total that was never built to divide evenly by it.
That mismatch is the entire reason the Global Forever stamp exists as its own product. Buying one closes the gap in a single purchase instead of guessing a combination, and USPS's own page states that its value tracks whatever the international first-ounce price is at the time it gets used, so it never needs replacing when that price moves.
USPS states that First-Class Mail International correspondence stays a letter only up to 3.5 oz, and pricing past the first ounce runs on the destination country's own price group rather than one flat figure. Weigh the envelope and check the destination before assuming any stamp count covers it.
The moment the contents make the envelope stiff or lumpy, it stops qualifying as correspondence and needs a package service with a customs form attached, stamps or not. Our international parcel delivery guide covers what that paperwork actually requires.
Letters and postcards are a Post Office product from end to end. What SMKlog checkout prices live is a boxed shipment, domestic or to one of the four countries it sells online, with the customs work built into buying the label rather than a stamp on an envelope.
USPS revises both prices on its own schedule and without lining them up against each other. Treat the figures above as what usps.com published on the date shown, and weigh anything heavier than a standard envelope before trusting a stamp count.
Three. USPS prices a standard 1 oz international letter or postcard at $1.75 when covered by its own Global Forever stamp. Two domestic Forever stamps at $0.82 each add up to only $1.64, eleven cents short, so the letter is undercharged. A third domestic stamp brings the total to $2.46, seventy-one cents over, which clears the price and still goes out.
Yes. USPS's own international mail page states plainly that a sender can use any other combination of stamps that adds up to the $1.75 price, not only the Global Forever stamp made for the purpose. Domestic Forever stamps count toward that total the same as any other denomination.
Because the two prices are set independently. The domestic Forever stamp is priced for a 1 oz letter that never leaves the country, currently $0.82, and the international letter price is set separately at $1.75. Nothing requires one to be a clean multiple of the other, which is exactly the gap the Global Forever stamp was created to close in a single purchase.
The flat $1.75 figure stops applying. USPS states that First-Class Mail International correspondence tops out at 3.5 oz in a letter shape, and pricing above 1 oz runs on the destination country's own price group rather than one number, so USPS points senders to its price list or online calculator instead of a fixed stamp count.
No. SMKlog's checkout prices parcel labels only, domestic packages plus self-service international labels to Canada, the UK, Germany and Australia, and does not sell postage stamps in any denomination. A boxed item goes through the calculator; a letter or postcard goes to the Post Office.