Originally Posted by Sunny Day

If a business issues you a check, they are legally bound to pay you. They should issue you a new check, after you notify them of the "stale check." You should notify them in writing with a copy of the check.
Should they not replace the check, explain to them, that they will have to escheat the money, to the state treasurer under state's unclaimed property laws. States take these laws very seriously, as they earn interest, until you finally claim your money.
Just using this club, usually works as when complain to the state treasurer, they run a full audit on the company. Makes an income tax or sales tax audit seem like fun. Besides getting the escheated funds, states have serious penalties for businesses who don't follow escheatment laws.