Reference Data Rate Center Directory DERBY, IA Rate Center DERBY — IA Data last updated: March 10, 2026 LATA 632 State IA Area Codes 1 Exchanges (NXX) 1 Carriers 1 Coordinates 40.93200223256975, -93.4556997032127 Area Codes 641 Top Carriers Carrier OCN NXX Count GRAND RIVER MUTUAL TEL CO 1888 1
