Texas ZIP codes run from the 733 prefix to the 885 prefix
Texas is large enough that USPS didn't give it one contiguous ZIP block the way it does for smaller states. The state's ZIP codes span 52 different three-digit prefixes from 733 up through 885, roughly tracking a north-to-south, then east-to-west numbering sweep that Texas shares at its edges with Oklahoma (73xxx), Louisiana (70xxx border areas), and New Mexico (88xxx). Phone numbers follow their own separate numbering system layered on top of this ZIP geography: Texas's area codes run on the overlay stacks each metro built up independently, with no fixed relationship to how many ZIP codes that same metro carries.
ZIP code count by major city
City population and ZIP code count don't move together in a straight line. A city's ZIP count depends more on its physical footprint and how spread out its delivery routes are than on how many people live there.
Dallas and Austin each get a deeper breakdown elsewhere on this site: Dallas's ZIP list includes four codes that actually belong to a legally independent town Dallas could never annex, and Austin's ZIP breakdown shows how its 74 codes split across two counties. Farther west on the same list, Lubbock's own ZIP breakdown covers a different kind of split: which of its 26 codes belong to Texas Tech's campus and which don't, since the campus isn't the only code some people assume it is.
ZIP codes per major Texas city (USPS-assigned place name)
| City | ZIP codes |
|---|---|
| Houston | 178 |
| El Paso | 137 |
| Dallas | 105 |
| San Antonio | 83 |
| Austin | 74 |
| Fort Worth | 56 |
Why El Paso has more ZIP codes than San Antonio, despite being smaller
San Antonio has more than double El Paso's population (roughly 1.5 million versus 680,000, per Census Bureau estimates), yet El Paso is assigned nearly twice as many ZIP codes. The more commonly cited reason isn't El Paso's location so much as its footprint: at roughly 248 square miles, El Paso is one of the largest Texas cities by land area, and its territory includes Fort Bliss, one of the US Army's largest posts, whose facilities carry their own separate ZIP codes. ZIP codes are drawn around mail-carrier routes and delivery volume, not population evenly divided across a city, so a large, sprawling service area anchored by a major military installation produces more, smaller zones than San Antonio's more compact urban core does.