Guides
Questions About ZIP Codes
Three questions readers ask about ZIP codes themselves, answered from the counts in the PlainZIP index.
Published October 9, 2026 by PlainZIP · written with AI tools from PlainZIP's database · figures passed the automated checks on October 9, 2026 · method
Guides
Guide
How many ZIP codes are there?
41,706 in the PlainZIP index: 33,774 residential, 7,382 PO Box or single-organization, 509 military.
Guide
Is a ZIP code the same as a ZCTA?
No: a ZCTA is the Census Bureau's area for a residential ZIP code; 7,915 ZIP codes have none.
Guide
PO Box, unique and military ZIP codes
7,382 codes serve post office boxes or one organization; 509 serve the military overseas.
Source: PlainZIP index (Census 2020 ZCTAs and GeoNames postal codes).