Area Code +1-301-(3123000...3123999) located in Bethesda, Maryland (MD), more detail is as below. Place International Dialing Code : 1 International Prefix : 011 National Prefix : 1 National Destination Code : 301 Subscriber Number From : 3123000 Subscriber Number To : 3123999 National Destination Code Length : 3 Uses National Destination Code : Yes National Significant Number Length : 10 Number Type : M (Mobile, Cellular) Carrier Name : NEW CINGULAR WRLS DC 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 : Bethesda Timezone : America/New_York Coordinated Universal Time : -05:00 Daylight Saving Time : Yes National Significant Number Minimum Length : 10 Latitude : 38.9800 Longitude : -77.1100 ‹ previous : +1-301-(3122000...3122999) next › : +1-301-(3124000...3124999) Dialling Instructions For trunk calls: 0 301 3123000 (Trunk Code + National Destination Code + Subscriber Number) For international calls: 011 1 301 3123000 (International Prefix + International Dailing Code +National Destination Code + Subscriber Number) Telephone Number List 3123000 ~ 3123999 (Count: 1,000) Example: +1-301-3123000 / 0111-301-3123000 (1301-3123000 / 1-301-3123000) +1-301-3123001 / 0111-301-3123001 (1301-3123001 / 1-301-3123001) +1-301-3123002 / 0111-301-3123002 (1301-3123002 / 1-301-3123002) +1-301-3123003 / 0111-301-3123003 (1301-3123003 / 1-301-3123003) +1-301-3123004 / 0111-301-3123004 (1301-3123004 / 1-301-3123004) ...+1-301-xxxxxxx / 0111-301-xxxxxxx (1301-xxxxxxx / 1-301-xxxxxxx) ...+1-301-3123995 / 0111-301-3123995 (1301-3123995 / 1-301-3123995) +1-301-3123996 / 0111-301-3123996 (1301-3123996 / 1-301-3123996) +1-301-3123997 / 0111-301-3123997 (1301-3123997 / 1-301-3123997) +1-301-3123998 / 0111-301-3123998 (1301-3123998 / 1-301-3123998) +1-301-3123999 / 0111-301-3123999 (1301-3123999 / 1-301-3123999)