Should North Tustin get its own ZIP code, it’s possible residents wouldn’t be on the hook for quite as high of a sales tax. The base sales tax in Orange County is 7.75%, for example.

The three priciest ZIP codes in Orange county were in Newport Beach, which led with 92661 having a median price of $4.35 million. The cheapest ZIPs were Laguna Woods 92637 at $382,500, ...