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 provided text describes the geographical coverage of area codes 903 and 430 within the North American Numbering Plan (NANP), specifically in the northeastern part of Texas, which includes cities like Texarkana, Tyler, and Sherman.