Learn Bank Policies
The Uniform Commercial Code doesn't require a bank to pay a check that's more than six months old. However, banks do have the ability to cash old checks. Policies vary depending on the bank and the type of check. Don't be deterred by checks that have expiration dates or state that they are void after 90 days. These expiration dates are not binding and can be waived by the bank.
Alert the Payer
If you plan to cash a check that's more than six months old, let the check writer know. Not every individual balances their checkbook and cashing the check could send the payer into the red. It's possible the individual doesn't even have the account open any more. Similarly, an old employer or business could have turned the funds over to the state and written the check off of their books. It may feel awkward to call after so long, but it's courteous and appreciated by the payer.
Get the Check Reissued
If you learn that the check issuer has closed their account or may not have sufficient funds, it's best not to cash the check. If you try to cash an old check and it declines, some banks will charge you a returned item fee. Instead, tell the check issuer that you will void the check if they can reissue you a new one.
Talk to the State
If you have a very old check, it's possible that the check-issuer has since cancelled the account and has no record of it. If the check-issuer refuses to issue a new check, you do have recourse. Businesses are required to turn over unclaimed wages, refunds and commissions to the state after a year. If they did so, your states's unclaimed property division will have record of the payment and can turn it over to you.