Area Coe 816 is an area code in the state of Missouri that covers the Kansas City Metropolitan Area and the city of St. Joseph to the north. The area code used to cover most of northwestern Missouri to the state's borders with Iowa, Kansas and Nebraska, but currently, the area code only shares a border with Kansas to the west and is surrounded on the other three sides by area code 660, the area code that was created by shearing off most of the former territory covered by 816.