Contact the Issuer
If you want to cash a check that's more than a few months old, contact the issuer. Especially if the check was written by a friend or family member, it's courteous to let the issuer know that you're cashing it. If the checking account holder keeps a low balance and has forgotten about the check, cashing it could put him into the red. This would be embarrassing for the payer and could be costly for both of you. Market Watch points out that your bank could also charge you a returned check fee if the check bounces.
Get It Reissued
In addition to contacting the issuer, you may want to ask that the check be reissued. Under the Uniform Commercial Code, banks don't have to honor checks that are over 6 months old. The issuer also may have given his bank instructions not to cash checks that are over 90 days old. Getting a new check is fairly easy if it was originally from a state or federal government agency. Most states will reissue tax refunds and other payments if the proper paperwork is submitted.
Work With the Bank
When you can't get an old check reissued, see what your bank can do. According to Bankrate, banks sometimes cash checks older than 6 months even though they are not required to do so. If the bank believes the check is valid and that the payer has the funds to cover the check, the bank may cash it. A "void after" notice on the check may not be valid if the issuer has not specifically instructed his bank to adhere to the expiration date.
Check With the State
A business may not have a record of checks that are over a year or two old. However, many businesses are required to turn over the funds for certain unclaimed payments -- such as payroll checks -- to the government of the state in which they are located. States maintain unclaimed property funds and reserve the resources for the rightful owners. If you've got an especially old check and the original business doesn't have record of the payment, contact your state government and inquire about any unclaimed funds in your name.