where is area code 737
512 and 737 are North American telephone area codes serving Central Texas, currently for telephones in and near Austin. Counties currently served by these area codes include Bastrop, Burnet, Caldwell, Hays, Travis, Milam and Williamson. Area code 512 was one of the original area codes established in October 1947.At the time, it covered most of the south-central portion of Texas, from the Gulf of Mexico to the Mexican border.rea code 512 was one of the original area codes established in October 1947. At the time, it covered most of the south-central portion of Texas, from the Gulf of Mexico to the Mexican border.