Despite this popular misconception, business checks do not grow stale/expire.  You can contact the insurance company, explain the situation and tell them you plan on cashing the check. If the insurance company tells you there may be an issue with it, you need to explain that you found it during the check of estate assets and that you will be more than happy as executor or trustee to show the proper paperwork. Normally this should be sufficient to resolve the matter.  In practice, personal checks are the only ones that grow stale and can be difficult to cash. Business checks usually don't have this issue.