AT&T services are offered in Iran through the network carrier RightTel.
"This past week, a spokesman for AT&T acknowledged that the company was providing voice and data service in Iran to its customers with American phones through a partnership with a local firm, RighTel. An employee at the Iranian company, fully owned by a state entity, confirmed the partnership. While the announcement that Airbus and Boeing will provide dozens of jetliners to Iranian carriers garnered worldwide headlines last month, the deal that AT&T clinched in March, making it the only American provider to offer phone service in Iran, flew under the radar... It remains unclear how AT&T and RighTel will settle accounts. A representative for AT&T said the company would not disclose information on financial arrangements made with the Treasury or with its Iranian partner. One possible clue: RighTel is owned by the Social Security Organization of Iran, a state entity that has large stakes in several domestic banks." ( The New York Times, "Sign of Thaw With Iran: American Cellphones Ringing in Tehran," 10/8/2016).