USPS now offers official ZIP Code boundary polygons

USPS offers an official national ZIP Code boundary dataset built from its delivery-address and location information. Unlike boundaries inferred from general geographic or commercial sources, these polygons are intended to represent USPS delivery areas, and they can change as delivery locations are added or altered. The dataset is updated quarterly, so it can help users keep ZIP Code maps aligned with shifting delivery distributions rather than relying on outdated boundary files.

The data is relevant to mapping, mailing, marketing, insurance, real estate, logistics, navigation, and transportation. Organizations can use the polygons as authoritative reference features, correct existing ZIP Code geography as changes occur, organize and display demographic information, or approximate delivery-location groupings for routing. USPS lists three access options: an internal version, an enterprise version with distribution limited to subsidiaries and partners, and a publication version with limited publication. Each receives four updates per year. Available materials include a briefing sheet, technical guide, sample data files in standard and GeoJSON formats, a license agreement, and an order form, giving prospective users resources to assess the data and its terms before obtaining it.