In North America, area code +1 307 is the U.S. state of Wyoming.
Country code +30 is Greece, but there are no valid numbers beginning +30 7.
Other countries may have domestic area codes like 307.
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, and many other countries use different prefixes.)
Area code 307 is in Wyoming, USA and includes the cities of Cheyenne and Casper, among others.
Wyoming (WY) uses area code 307.
The telephone area code for the entire state of Wyoming is 307, which is +1 307 in international format. (+1 is the telephone country code for the United States.)
Ashburton, New Zealand is in the Canterbury Region, on the coast of the South Island. The country calling code for Ashburton is 302, 303, 307. 308, and 908. The country calling code is +64.
307 Designates a Gang from Wyoming, usually from the state Penitentiary in Rawlins, Wy. 307 is Wyoming's area code.
The country code and area code of Changhua, Taiwan is 886, 47.
The country code and area code of ChillÌÁn, Chile is 56, 42.
The country code and area code of Asturias, Spain is 34, 884.
The country code and area code of Arganil, Portugal is 351, 235.
The country code and area code of Badajoz, Spain is 34, 824.
The country code and area code of Alava, Spain is 34, 845.
The country code and area code of Gelephu, Bhutan is 975, 6.
The country code and area code of Baghdad, Iraq is 964, 1.