There are a variety of reasons why a store may decline to accept a personal check; common reasons are that you have a negative history with the check verification system or that the system suspects fraudulent activity. It's best to contact your bank or the check verification company (usually TeleCheck or Certegy) to pinpoint the exact problem.((https://www.askcertegy.com/CheckSearch.jsp))((https://getassistance.telecheck.com/faq/))