Guide

Ryszard Cieplechowicz: a ZCTA is not a ZIP code

The Tampa Bay tables are organized by ZCTA. Here is why that is not the same as the ZIP code on a letter.

A ZIP code is a USPS delivery route system. A ZIP Code Tabulation Area (ZCTA) is a Census Bureau area built to approximate it so that statistics can be published for it.

Why it matters

• One ZCTA can cross county lines. The studies assign each to the county with the largest land-area share in the 2020 Census relationship file.
• Some ZIP codes, such as those for a single large building, have no ZCTA of their own.
• A ZCTA label can match the ZIP digits and still describe a slightly different area.

So look up an address by its ZCTA with care, and read the county assignment as approximate near boundaries. See the selection method and the data hub.