Greater Katy Area is the term often used to refer to a suburban region on the west side of the Greater Houston metropolitan area roughly corresponding to the boundaries of the Katy Independent School District. Many people and businesses in this area have a Katy address, but are not part of the city of Katy. This area includes the suburbs that surround the Katy city limits west to Pederson road, roughly east to State Highway 6, north to FM 529, and south to FM 1093/ Westpark Tollway Parkway. While these boundaries are not exact, it gives a rough outline of what most people consider Greater Katy, and what the USPS designates as "Katy, Texas" by assigning that city to addresses within zip codes that fall in this region. Most of Greater Katy is to the east of the city of Katy toward Houston and includes surrounding suburban areas and unincorporated areas that are not in the Houston city limits. The region includes parts of Harris County, Fort Bend County, and Waller County much as the City of Katy does. Greater Katy is one of the fastest-growing portions of the Houston metropolitan area and the state of Texas as a whole.