For a standard 1 oz letter, the answer to how many forever stamps for international letter delivery is one Global Forever stamp. It costs $1.75 and covers a 1 oz letter to any other country. If you only have regular domestic Forever stamps at $0.82 each, you need 3.
The count changes once the letter gets heavier, goes to Canada or Mexico, or is lumpy enough to need a surcharge. The tables below use the USPS price list effective July 12, 2026.
How many forever stamps for international letter delivery at 1 oz?
One. The USPS international letters page says a Global Forever stamp covers a 1 oz letter or a postcard going to any other country. That includes the UK, England, Germany and Australia, and it works for Canada and Mexico too.
Global Forever stamps never expire. You can buy a roll or book now and use the stamps years from now at the same value, even if prices rise.
Can you use regular Forever stamps on an international letter?
Yes, but a domestic Forever stamp is worth only its $0.82 domestic price. It does not stretch to the international rate. You have to add stamps until the total reaches the international price.
For a 1 oz letter at $1.75, two domestic stamps total $1.64, which is short. Three total $2.46, which covers it. You overpay by $0.71.
For other mail types, the general stamp counting guide walks through the same math.
How many forever stamps for international letter weights up to 3.5 oz?
International letters go up to 3.5 oz. Here is what each weight costs for countries other than Canada and Mexico, and how many stamps of each type it takes.
| Weight not over | Price | Global Forever stamps | Domestic Forever stamps ($0.82) |
|---|---|---|---|
| 1 oz | $1.75 | 1 | 3 |
| 2 oz | $3.50 | 2 | 5 |
| 3 oz | $5.25 | 3 | 7 |
| 3.5 oz | $5.75 | 4 | 8 |
The 3.5 oz row is the tricky one. Seven domestic stamps total $5.74, which is one cent short of $5.75. You need an eighth.
With Global Forever stamps, a 3.5 oz letter takes 4, because 3 total only $5.25.
Weigh the finished letter before you stamp it. The envelope, paper and any insert all count toward the weight.
How many stamps to send a letter to the UK, Germany or Australia?
The answer is the same for all three, and for any other country outside North America. The UK and England, Germany and Australia all pay the “all other countries” price shown in the table above. A 1 oz letter takes one Global Forever stamp, or 3 domestic Forever stamps.
USPS sorts destinations into price groups, but every group other than Canada (group 1) and Mexico (group 2) pays the same letter price, so the count for the UK matches Germany, Australia, Japan or anywhere else overseas.
Do Canada and Mexico cost the same?
Only for a 1 oz letter, which is $1.75 to either country. Beyond 1 oz, Canada and Mexico each have their own lower prices.
| Weight not over | Canada | Mexico | Domestic stamps for Canada | Domestic stamps for Mexico |
|---|---|---|---|---|
| 1 oz | $1.75 | $1.75 | 3 | 3 |
| 2 oz | $2.35 | $2.60 | 3 | 4 |
| 3 oz | $2.95 | $3.50 | 4 | 5 |
| 3.5 oz | $3.50 | $4.15 | 5 | 6 |
A Global Forever stamp is worth $1.75, so a heavier letter to Canada needs two of them from 2 oz up. Domestic Forever stamps often give a tighter fit here.
Worked examples for common letters
- A one page letter to a friend in the UK weighs under 1 oz. Use one Global Forever stamp, or three domestic Forever stamps.
- A 2 oz letter to Germany costs $3.50. That is 2 Global Forever stamps, or 5 domestic stamps for $4.10.
- A 2 oz letter to Canada costs $2.35. Three domestic stamps total $2.46 and cover it.
- A 3 oz letter to Mexico costs $3.50. Five domestic stamps cover it at $4.10.
These examples show why a single count never fits every letter. Always check weight and destination first, then decide how many forever stamps for international letter mailing you really need.
What does a nonmachinable letter add?
USPS adds $0.49 to a nonmachinable international letter. The surcharge applies to envelopes that are lumpy or rigid, that have clasps, string or buttons, or that are square or vertical (taller than they are wide). A stiff item tucked inside the envelope can trigger it.
A 1 oz nonmachinable letter to the UK costs $2.24. Three domestic stamps cover that, and so do two Global Forever stamps. If you are unsure, ask a clerk at the counter before you drop it in a box.
What about postcards and large envelopes?
A postcard to any country costs $1.75, the same as a 1 oz letter, so one Global Forever stamp covers it. On the USPS letters page a postcard is 5 1/2 to 6 inches long, 3 1/2 to 4 1/4 inches high and at most 0.016 inch thick.
A large envelope, also called a flat, can weigh up to 15.994 oz. Pricing starts at $3.30 for 1 oz.
Heavier flats are priced by weight and destination group, and the USPS letters page sends you to its price calculator rather than listing them. Our stamp calculator does the stamp math once you know the price, or ask at the counter.
The domestic version is covered in our guide to a large envelope by weight.
Do you need a customs form for an international letter?
Not for plain correspondence or nonnegotiable paper documents. A customs form is required if the envelope holds items with cash value, trading cards, bookmarks or stickers. Letters and large envelopes sent as First-Class Mail International can hold only documents, so anything else belongs in a package.
If a package might face duties at the destination, the international duty estimator gives you a rough idea of the charges.
How to put the stamps on and send it
- Weigh the letter and check the table above for the price.
- Write the full address, including the destination country.
- Place the stamps in the upper right corner, leaving room for the postmark.
- Add your return address on the upper left.
- Hand it to a clerk or drop it in a collection box.
Buying stamps in bulk? See how many stamps are in a sheet.
Rolls are covered in a separate guide on stamps in a roll.
Bottom line on stamps for an international letter
For a standard 1 oz letter, one Global Forever stamp is the whole answer. Domestic Forever stamps work as well, as long as the total hits the international price. Weight, the Canada and Mexico price groups and the $0.49 nonmachinable charge are the three things that change the count.
