Area Code +1-240-(5100000...5100999) located in Upper Marlboro, 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 : 5100000 Subscriber Number To : 5100999 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 : XO MARYLAND LLC 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 : Upper Marlboro Timezone : America/New_York Coordinated Universal Time : -05:00 Daylight Saving Time : Yes National Significant Number Minimum Length : 10 Latitude : 38.8200 Longitude : -76.7500 ‹ previous : +1-240-(5099000...5099999) next › : +1-240-(5101000...5101999) Dialling Instructions For trunk calls: 0 240 5100000 (Trunk Code + National Destination Code + Subscriber Number) For international calls: 011 1 240 5100000 (International Prefix + International Dailing Code +National Destination Code + Subscriber Number) Telephone Number List 5100000 ~ 5100999 (Count: 1,000) Example: +1-240-5100000 / 0111-240-5100000 (1240-5100000 / 1-240-5100000) +1-240-5100001 / 0111-240-5100001 (1240-5100001 / 1-240-5100001) +1-240-5100002 / 0111-240-5100002 (1240-5100002 / 1-240-5100002) +1-240-5100003 / 0111-240-5100003 (1240-5100003 / 1-240-5100003) +1-240-5100004 / 0111-240-5100004 (1240-5100004 / 1-240-5100004) ...+1-240-xxxxxxx / 0111-240-xxxxxxx (1240-xxxxxxx / 1-240-xxxxxxx) ...+1-240-5100995 / 0111-240-5100995 (1240-5100995 / 1-240-5100995) +1-240-5100996 / 0111-240-5100996 (1240-5100996 / 1-240-5100996) +1-240-5100997 / 0111-240-5100997 (1240-5100997 / 1-240-5100997) +1-240-5100998 / 0111-240-5100998 (1240-5100998 / 1-240-5100998) +1-240-5100999 / 0111-240-5100999 (1240-5100999 / 1-240-5100999)