Who can join a credit union? Laws have been implemented to assess who is allowed to enter a credit union in that they require that a person is a member of a specific field of membership such as a church group, community group or employee group of a corporation. If you are a member of a group, you are part of what is called a common bond and can join in on the credit union and partake in its services. For more information, contact VFCU at the Harlingen Credit Union branch at (956) 425-5668, or the Brownsville Credit Union branch at (956) 546-3108.