Offer your thoughts or opinion on the input financial query or topic using your financial background.

Found an old un-cashed paycheck. How long is it good for? What to do if it's expired?
Look up escheatment. Companies that have unclaimed property are supposed to send it to your State government. They should have a unclaimed property department of some sort. In short, the company is going to have to pay either you, or your State (In Your Name) so they have to pay it either way. It would be easier for them to just give you new check. Expect them to give you some grief in verifying it has not been cashed and such... but if you have the original, in hand, it shouldn't be too bad. A 'Lost' check may be harder to get replaced. Not a lawyer, don't want to be.