Area Code +1-240-(3977000...3977999) located in Frederick, Maryland (MD), more detail is as below. Place International Dialing Code : 1 International Prefix : 011 National Prefix : 1 National Destination Code : 240 Subscriber Number From : 3977000 Subscriber Number To : 3977999 National Destination Code Length : 3 Uses National Destination Code : Yes National Significant Number Length : 10 Number Type : G (Geographic Land Line, Fixed Line) Carrier Name : MCI WORLDCOM COMM MD Click here to buy United States Area Code Database Other Information Language Code : en (English) Country Number : 840 (United States) Country Code : US (United States) Region Code : MD Region Name : Maryland City : Frederick Timezone : America/New_York Coordinated Universal Time : -05:00 Daylight Saving Time : Yes National Significant Number Minimum Length : 10 Latitude : 39.4200 Longitude : -77.4100 ‹ previous : +1-240-(3976000...3976999) next › : +1-240-(3978000...3978999) Dialling Instructions For trunk calls: 0 240 3977000 (Trunk Code + National Destination Code + Subscriber Number) For international calls: 011 1 240 3977000 (International Prefix + International Dailing Code +National Destination Code + Subscriber Number) Telephone Number List 3977000 ~ 3977999 (Count: 1,000) Example: +1-240-3977000 / 0111-240-3977000 (1240-3977000 / 1-240-3977000) +1-240-3977001 / 0111-240-3977001 (1240-3977001 / 1-240-3977001) +1-240-3977002 / 0111-240-3977002 (1240-3977002 / 1-240-3977002) +1-240-3977003 / 0111-240-3977003 (1240-3977003 / 1-240-3977003) +1-240-3977004 / 0111-240-3977004 (1240-3977004 / 1-240-3977004) ...+1-240-xxxxxxx / 0111-240-xxxxxxx (1240-xxxxxxx / 1-240-xxxxxxx) ...+1-240-3977995 / 0111-240-3977995 (1240-3977995 / 1-240-3977995) +1-240-3977996 / 0111-240-3977996 (1240-3977996 / 1-240-3977996) +1-240-3977997 / 0111-240-3977997 (1240-3977997 / 1-240-3977997) +1-240-3977998 / 0111-240-3977998 (1240-3977998 / 1-240-3977998) +1-240-3977999 / 0111-240-3977999 (1240-3977999 / 1-240-3977999)