Southside Bank, Flower Mound Basic Info Reviews Routing Numbers Map & Direction Name: Southside Bank, Flower Mound Main Office: No Service: Full Service Brick and Mortar Office Location: 2341 Justin Road Flower Mound, Texas 75028 Denton County View other branches Phone: 972-434-4686 Please enable JavaScript to view the comments powered by Disqus. Routing NumberProcess ACH TransferProcess Wire Transfer111923607YY111924237YY311981533YY From: To: