Area codes 903 and 430 are telephone
area codes in the
North American Numbering Plan (NANP) for the northeastern part of the
U.S. state of
Texas, including
Texarkana,
Tyler, and
Sherman. The numbering plan area begins just north and east of the
Dallas–Fort Worth metroplex, and extends to the Oklahoma, Arkansas, and Louisiana state borders. Area code 903 was created November 4, 1990 in a split of
area code 214. Area code 430 was assigned to the same service area on February 15, 2003 in creation of an
overlay. Before October 18, 1980, area code 903 was assigned to an area in northwestern Mexico.
History
From 1962 until October 18, 1980, area code 903 was an area code for parts of northwestern
Mexico served by Telefónica Fronteriza, which homed on AT&T lines in the United States rather than Telefonos de Mexico (
Telmex). Telmex and the Mexican government forcibly acquired the TF exchanges, and in 1980, Telmex reorganized the area codes of the country, assigning 6 as the initial digit of 8-digit numbers in the northwest. At this point, 903 was withdrawn from use and replaced with
area code 706,[1] as one of two area codes for alternative dialing into certain parts of Mexico from the United States. The other area code used for this was
905. 706 and 905 were
dial-around codes that replaced +52(5) for
Mexico City and +52(6) for northwestern Mexico. In February 1991, 706 and 905 were withdrawn pending assignment within the NANP service area.