Editorial Policy

What PlainZIP publishes

Figures about ZIP codes and the places they serve, taken from public files and shown with their source and vintage. Where a figure is an estimate, its survey years go with it; where the estimate is uncertain, its margin does too. Comparisons (a ZIP's rank in its town or county, the gap between a city's highest- and lowest-income ZIP codes) are computed from the same figures and say how.

What it does not publish

PlainZIP does not grade places as good or bad to live in, does not publish anything about named individuals, and does not invent figures to fill a gap: a missing value is shown as missing. It does not accept payment to change, add or remove content, and advertising never decides what a page says.

How pages are written

The sentences on ZIP code, city and county pages are built from each place's own figures by fixed rules, so they change when the data changes. PlainZIP's owner uses AI tools to write code, templates and explanatory text; the numbers come from database queries, and every template and analysis is checked against the source tables by automated checks and read by separate AI review agents before it is published. No person reviews each page; PlainZIP's owner answers for what is published (methodology).

Updates and corrections

Data is reloaded when a source publishes a new vintage. The American Community Survey's 5-year estimates usually appear each December, FHFA's annual ZIP house price index in the spring, and ZIP Business Patterns and the IRS ZIP files once a year. Errors are corrected at their source and listed on the corrections page. PlainZIP's owner is named on the About page; write to hello@plainzip.com.