Union Square Credit Union's field of membership is open to those who have the following common bond:
- Persons who live, work, worship or attend school in Archer, Baylor, Clay, Wichita or Wilbarger Counties, Texas; or Cotton or Tillman Counties, Oklahoma;
- Spouses of persons who died while within the field of membership of this credit union;
- Organizations of such persons.
- And members of the family of such persons.