LetterAgent
Mail physical letters by just asking your AI assistant.
Home > Guides > Buying a single stamp
Yes. Post office counters sell individual stamps, and that one stamp covers a standard one-ounce letter. Drugstores, grocery checkouts, and office-supply stores mostly sell books or rolls only, so if you need exactly one, the post office counter is your destination.
| Where | Singles available? | What to know |
|---|---|---|
| USPS post office counter | Yes | The reliable option; ask for one First-Class stamp |
| USPS self-service kiosk | Usually yes | Many locations have kiosks in the lobby, open longer hours than the counter |
| Canada Post outlet counter | Yes | Ask for one Permanent stamp for a standard domestic letter |
| Drugstore or grocery checkout | Rarely | Almost always books of stamps only |
| ATM-style stamp vending machines | Sometimes | Fading out; surviving machines mostly dispense books |
One standard stamp covers a regular envelope, up to one ounce, mailed domestically. One ounce is roughly three to four sheets of paper in a standard envelope. If your letter is thicker, heavier, or oddly shaped (square envelopes, rigid contents), it needs more postage, and the counter staff will weigh it and tell you. An international letter needs more than one domestic stamp. When in doubt, have the counter weigh it: guessing wrong means the letter comes back to you days later marked for insufficient postage.
Buy a Forever stamp (in the US) or a Permanent stamp (in Canada). These stay valid for a standard domestic letter no matter how many rate changes happen afterward, so the stamp you buy now still works in five years. This is the whole point of them: infrequent mailers never have to think about whether their old stamps still count. Keep the single stamp in your wallet or on your desk, and you are permanently one letter away from being able to mail it.
Not at all. Counter staff sell single stamps all day: it is one of the most ordinary transactions at any post office. If the line looks long for a one-stamp errand, check for a self-service kiosk in the lobby, which handles stamps without the wait. And if even that feels like too much errand for one letter, consider skipping the stamp entirely: services like LetterAgent fold postage into a per-letter quote, so you never buy stamps at all.
Then one stamp is not enough, and the fix depends on where you are. In the US, each additional ounce costs extra, and the counter can sell you the exact additional-ounce stamps. In Canada, the step structure is similar for lettermail. Non-machinable items, square envelopes, and anything lumpy or rigid carry surcharges because they cannot run through sorting machines. The practical rule: anything beyond a few sheets of paper gets weighed at the counter before you seal it.
Ready to mail it? Send your letter with LetterAgent: describe it to your AI assistant, approve the exact quoted price, and it is 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