LetterAgent
Mail physical letters by just asking your AI assistant.
Home > Guides > Postcard vs letter
Send a postcard when the message can be public and you want the cheapest postage: invitations, thank-yous, and greetings. Send a letter when the contents are private, sensitive, or longer than a few sentences. The whole decision comes down to one trade-off: a postcard has no envelope, so everyone who handles it can read it.
| Postcard | Letter | |
|---|---|---|
| Privacy | None. Message and photo sit out in the open. | Sealed in an envelope; only the recipient reads it. |
| Postage | Cheaper than a letter | Standard letter rate |
| Space | A few sentences, one side | As many pages as you need |
| First impression | Casual, cheerful, personal | Formal or neutral, depending on the letter |
| Best for | Invitations, thank-yous, greetings, reminders | Anything sensitive, formal, or long |
Privacy, entirely. A postcard's message faces outward through every step: the carrier who picks it up, the sorting facility, the recipient's mailroom, a roommate who grabs the mail first. For a birthday greeting that's a feature, not a bug. For anything with an account number, a health detail, a financial figure, or a personal confidence, it's a dealbreaker.
The space constraint is the second cost. A standard postcard holds a short message, not an argument. If your note runs longer than a paragraph or two, you'll be cramming handwriting into the card's edges, which defeats the cheerful simplicity that makes postcards work. There's also no room for extra documents: no enclosure, no business card, no second page.
Postcards win on cost, speed of preparation, and charm. The postage is cheaper than a letter's, there's no envelope to buy or seal, and the message is visible the instant the recipient picks it up: no opening required, which means it gets read. For bulk mailings like event invitations or thank-you notes, those small savings and the zero-assembly effort add up fast. A postcard also photographs well and gets pinned to fridges in a way letters don't.
There's a marketing angle too. Businesses use postcards for promotions precisely because the message can't be ignored: the recipient reads it before deciding whether to keep it, whereas a plain envelope might go straight to recycling. If your goal is "seen by everyone," the postcard's lack of privacy is an asset.
Anything you'd be uncomfortable with a stranger reading. That includes checks or money orders, account and routing numbers, passwords or access codes, medical information, legal disputes, and personal news the recipient might not want announced (a breakup, a diagnosis, bad news of any kind). A good test: if you'd flinch seeing it quoted back to you by someone you don't know, it belongs in a sealed envelope.
Also skip anything you need proof of sending. Postcards can't be sent certified or registered in the usual way, and there's no envelope to keep a copy of. If the message matters enough that you'd want a paper trail, that's your answer: send a letter.
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