International Calling International Calling To dial direct, dial 011 + country code + city code + number. Note: Calls to Canada, Puerto Rico, Guam, U.S. Virgin Islands, Northern Mariana Islands, and many Caribbean countries do not require you to dial 011..n other words, to call these countries you only need to dial 1 + (area code) + number. No country, city, or international access codes are required.Customers calling from the United States to a mobile number in Mexico must dial a 1 after the Mexico country code of 52 and before the 10-digit local number.