A letter travels on postage bought at face value, the same everywhere it is sold. Nothing here is priced by us.
What the Global Forever stamp actually buys
USPS names three shapes on its First-Class Mail International page, and each carries its own ceiling. Figures below are quoted from that page, read 2026-08-25.
| Piece | Weight ceiling | Price |
|---|---|---|
| Standard-sized letter or postcard | 1 oz | Starts at $1.75 |
| Letter, over 1 oz | Up to 3.5 oz | Priced by the destination country's price group, no single figure published |
| Large envelope or flat | Up to 15.994 oz | Priced by the destination country's price group, no single figure published |
USPS is explicit that a single sticker price only exists at the 1 oz line: prices for envelopes heavier than 1 oz, oversized, or unusually shaped are based on the destination country's price group, and the page points senders to its own online price calculator rather than a printed table. That is a real difference from the domestic Forever stamp, where every ounce up to 3.5 has a published number on Notice 123. Anyone weighing a heavier envelope should run the destination through USPS's own calculator before assuming $1.75 covers it, because past 1 oz it almost never does.
The one question that decides whether a form is needed
USPS draws the customs-form line at what is inside the envelope, not at the country it is going to. Per usps.com, read 2026-08-25: “If you're just sending correspondence (no trading cards, bookmarks, stickers, etc.) or nonnegotiable documents (just paper; no cash, checks, or other items that have cash value), you don't need a customs form.”
Plain correspondence, no form
A letter, a card, a printed document with nothing enclosed clears the border on the stamp alone. This is the case that covers most personal mail.
Anything with cash value, a form
Trading cards, stickers, a keepsake taped inside a birthday card, a coin, all count as goods rather than correspondence. USPS offers an online tool to complete the form once that line is crossed.
A gift belongs on a different page
Once an envelope is really carrying an object rather than paper, the honest move is to stop calling it a letter. Our customs documents guide walks through the CN22 and CN23 forms that apply once real goods are involved.
Canada does not get its own price or its own form
Canada shows up by name on USPS's own First-Class Mail International page, grouped with Great Britain and Australia as an example destination among the more than 180 the service reaches. Nothing in what we read singles Canada out for a different letter price or a different customs threshold. What does change once mail turns into merchandise is duty and tax on the receiving end, which is a Canada Border Services Agency matter rather than a USPS one; our Canada shipping guide covers that side for anything that has grown past a letter into an actual parcel.
Why this page has no checkout button
SMKlog's calculator prices and prints parcel labels: a box or an envelope with weight and dimensions, moving between two US addresses or out to Canada, the UK, Germany and Australia. A letter under an ounce, paid for with a stamp, is not that product — and USPS's own international postage never is, as our USPS international shipping page says plainly for packages too. If what is actually being sent has grown into a real parcel, whether because it is heavier than 15.994 oz, boxy rather than flat, or full of goods rather than paper, the honest next step is to price it as a package rather than keep hunting for a bigger stamp. The paperwork that comes with that and the carriers that actually sell the export service are both covered elsewhere on the site.
Where this comes from
- USPS, First-Class Mail International — the Global Forever stamp price, weight ceilings for letters and large envelopes, and the customs-form rule for correspondence. Read 2026-08-25.
USPS revises international prices and rules without much notice, most recently alongside its domestic rate changes. Treat the figures above as what USPS published on the date shown and check usps.com directly before mailing anything time-sensitive or valuable.
Common questions
How do I mail a letter internationally from the US?
Put a Global Forever stamp on it instead of a domestic Forever stamp, address it the same way you would a domestic letter with the destination country spelled out on the last line, and hand it to a carrier or drop it in a mailbox. USPS states the Global Forever stamp covers a 1 oz letter or postcard to more than 180 countries, Canada included.
How much does it cost to mail a letter to Canada?
The same as any other Global Forever destination: stamps for a standard-sized letter or postcard up to 1 oz start at $1.75, per usps.com, read 2026-08-25. Canada is named on USPS's own page as one of the countries this stamp reaches, so nothing about the price changes for it.
Do I need a customs form to mail a letter overseas?
Not for a plain letter. USPS states that if you are only sending correspondence, or nonnegotiable documents with no cash value, no customs form is required. A form is needed once the envelope carries anything else, a photo, a card with a keepsake taped in, a few trading cards, and USPS offers an online tool to fill one out.
How heavy can an international letter be before the price changes?
One ounce is the flat-price cutoff. Past that, USPS prices envelopes heavier than 1 oz, oversized, or unusually shaped by the destination country's price group rather than a single published number, and directs senders to its online price calculator. A large envelope or flat can still travel this way up to 15.994 oz; heavier or boxier items stop being letter mail entirely.
Can SMKlog sell me an international letter stamp or label?
No. SMKlog's checkout produces parcel labels, US domestic plus four lanes abroad (Canada, the UK, Germany and Australia), and never letter postage. A letter travels on a stamp bought from USPS or a retailer that sells them at face value, not through a carrier checkout, and nothing on this page can be bought from us.
More on mailing and international shipping
Every guide linked above is free to read with no account. See the full shipping cost guide index