Southwestern National Bank Share: Banks & Banking Associations Southwestern National Bank Visit Website 1528 S El Camino Real, Suite 301 San Mateo, California 94402 (650) 418-7423 About Map About Established in 1997, Southwestern National Bank provides deposit and lending solutions to small and medium size business segments. We strive to build long term valued relationships. What's Nearby? Distance: 5 10 15 20 25 50 mi.