LetterAgent
Mail physical letters by just asking your AI assistant.
Home > Guides > Letters between the US and Canada
Mailing a letter from the US to Canada, or the reverse, works like mailing from anywhere else: only the recipient's address matters. US recipients get a letter billed in USD; Canadian recipients get one billed in CAD with sales tax at checkout. You needn't share the recipient's country, and no special postage knowledge is required.
| US → Canada | Canada → US | |
|---|---|---|
| Address format | Canadian format: name, street, then city + province abbreviation + postal code on one line, two spaces before the code (Toronto ON M4B 1B3). | US format: name, street, city, two-letter state abbreviation, ZIP code. |
| Letter billing | Billed in CAD; applicable Canadian sales tax is added at checkout as its own line item. | Billed in USD; no sales tax. |
| Write the country? | Writing "Canada" on the last line is good practice, especially if you're dictating the letter to an assistant that may not know. | Writing "USA" on the last line is good practice for the same reason. |
| Registered option | Canada Registered Mail gives tracking and proof of delivery. | US Certified Mail gives tracking and proof of delivery. |
A few practical details worth knowing. First, the postal code: Canadian codes are six characters with a space in the middle (K1A 0B1), and leaving out the space or mashing it together can slow automated sorting: write it exactly as the recipient gives it. Second, province abbreviations aren't always what Americans guess: British Columbia is BC, Newfoundland and Labrador is NL, and Quebec is QC. Third, apartment or unit numbers go before the street address in Canadian format ("Apt 4-123 Main St"), not after.
Another real-world point: if your letter comes back undeliverable, the sender address shown through the window envelope acts as the return address: it comes back to wherever you put. For cross-border mail, make sure the return address is complete enough for the other country's postal service to deliver it back to you; a partial return address on an international piece often just gets discarded.
No. Ordinary letters (birthday cards, thank-you notes, invitations, personal correspondence) are documents, not goods, and they never need a customs declaration. The only time customs enters the picture is if you slip something into the envelope that counts as merchandise. (LetterAgent's envelope carries just the letter: no inserts, so this doesn't come up.)
Longer than domestic mail in either direction. Don't plan around a specific number of days: border crossings add variability that no one can promise away. If the letter matters (an invitation, a thank-you before a deadline, holiday cards), send it noticeably earlier than you would a domestic letter. And if you need proof it arrived, the registered options on both sides give you tracking and delivery confirmation.
Ready to mail it? Send your letter with LetterAgent: describe it to your AI assistant, approve the exact quoted price, and it's printed and mailed.
LetterAgent is a working name. Prices include print, postage, and our service fee. US prices in USD, Canadian prices in CAD (Canadian prices exclude applicable sales tax, added at checkout). Currently in private testing.
Need help? Ask your assistant: it can check a job's status any time. If it ever can't handle something: hello@getletteragent.com