Just found an old check I forgot about and started wondering—how long is a check actually good for? Turns out it's more complicated than I thought. So technically checks don't really expire, but they go "stale" after a while, and banks can decide whether to process them or not. The whole thing exists mainly to protect the account holder since balances change and you can't assume funds are still there months later. For personal checks, you've got about 6 months before your bank isn't required to cash it anymore. Business checks usually say "void after 90 days" but that's more of a suggestion—they're typically good for 6 months too unless they specifically state one year. Cashier's checks are different though. They don't have expiration dates but if you hold one too long, the bank might do something called "escheat" where they transfer it to the state as unclaimed property. That's annoying because you'd have to request a replacement from the issuing bank. Money orders work similarly—no expiration date technically, but you might lose value if you don't cash it within 1-3 years depending on your state. If you find an old check lying around, your best move is to try depositing it first. If that doesn't work, contact whoever issued it and ask them to reissue. Or you can go directly to their bank and see if a banker can verify the funds and help you cash it. Honestly the safest thing is just depositing checks immediately when you get them. Way less hassle than figuring out how long checks are good for later.