Oak Park Leaders Lobby for a Separate ZIP Code : Boundaries: Residents say they would get lower insurance rates with their own postal designation.

Leaders of Oak Park want their unincorporated community to have its own ZIP code so insurance and utility companies and other agencies would stop assuming that the area is part of Los Angeles County.

The eastern Ventura County community is served by the Agoura Hills post office just over the Los Angeles County line. But its residents are tired of “cross-county confusion” that costs them money, according to a letter from Supervisor Maria VanderKolk’s office to the U.S. Postal Service.

Oak Park residents have found that their association with Los Angeles County means that they pay more in insurance and car registration fees, said Ron Stark, a member of the Oak Park Municipal Advisory Council.

VanderKolk’s office sent the letter to the Postal Service’s regional office in Van Nuys earlier this month. Postal Service spokesman John Conti said the request will be reviewed on both a regional and national level. However, he said, it is rare for the post office to change a ZIP code for reasons other than easing its delivery routes.

Changing a ZIP code can cost the post office several hundred thousand dollars because it must update all its books and computer codes, Conti said.

“Just to put one in because someone wants community identity . . . or is looking for a better tax break or insurance break or whatever is not something we’re concerned with,” Conti said. “ZIP codes were established for mail processing.”