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Home > Guides > Check vs online payment
Pay online for speed and a clean receipt; mail a check when you want float (the days before the money leaves your account), a stop-payment option, or the recipient only accepts paper. Bank bill-pay splits the difference: you pay online, and the bank mails a check for you.
| Mailed check | Online payment | |
|---|---|---|
| Speed | Days: mail transit plus clearing time | Minutes to a couple of days |
| Proof of payment | Cancelled check image from your bank, plus your mailing receipt if you track it | Confirmation number and transaction record |
| Can you undo it? | Yes: stop payment before it's cashed | Usually no: most online payments are final once sent |
| Float | Yes: money leaves your account days after you mail it | No: money moves almost immediately |
| Risk | Mail theft and check washing | Wrong account number, phishing, or a compromised biller portal |
Control over timing and a genuine undo button. A mailed check takes days to arrive and days more to clear, which is the "float" people talk about: the money stays in your account until the check is presented. More importantly, you can stop payment on a check that hasn't been cashed. If a contractor never did the work, or you mailed the check to the wrong address, a stop-payment order freezes it. Try doing that with a completed online transfer.
The cost is risk in transit. A check in the mail carries your name, account number, routing number, and signature: everything needed to fake you. Check washing is the classic attack: thieves steal the envelope, erase the ink with chemicals, and rewrite the payee and amount. Two defenses actually work: mail checks in a security envelope from inside a post office or a locked box (not a curbside mailbox with the flag up), and write with a gel-ink pen, whose ink soaks into the paper fibers and resists washing far better than ballpoint ink.
Speed and certainty. The payment arrives in minutes or days, you get a confirmation number instantly, and there's no envelope to lose. For recurring bills, autopay removes the whole task from your calendar. The receipt is also cleaner: a transaction record with the exact timestamp, instead of a cancelled check you have to go find in your bank's document archive.
The trade-off is finality. Most online payments, bill-pay transfers, and especially wire or peer-to-peer payments, can't be reversed once sent. A typo in the account number can send your money to a stranger, and recovery is a process, not a phone call. Online payment is also only as safe as the channel: a spoofed biller email or a compromised account can redirect a payment invisibly. Double-check the destination before you hit send, because there's no stop-payment safety net.
Yes: your bank's bill-pay service. You schedule the payment online, and the bank either sends it electronically or prints and mails a paper check on your behalf. You get the online convenience (scheduling, reminders, records) while the recipient gets a check they can deposit. The check comes from the bank's processing center, which also sidesteps the curbside-mailbox theft problem.
For proof of payment, both methods work if you keep records. Online, save the confirmation number. By mail, keep a copy or photo of the check and send it with tracking or certified mail so you can prove when it arrived. And if the recipient is a landlord or small business that only takes paper, the question answers itself: mail the check, but mail it smart.
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.
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