US ZIP / ZCTA County & District Lookup

Paste a US ZIP code or ZIP+4 and get a structured Census geography result with county, county FIPS, state, and 119th Congressional District mappings. This is designed for both quick manual checks and API or batch workflows.

Quick example: 90210 returns Los Angeles County, county FIPS 06037, plus every supported congressional-district relationship. ZIP+4 such as 90210-1234 is accepted and normalized automatically.

US ZIP code to county and FIPS lookup

Use this Actor when you need a ZIP code county lookup, ZIP to county conversion, county FIPS lookup, or a structured Census ZCTA mapping. Results include state name and FIPS, county names and FIPS codes, overlap percentages, and a primary county selected by the largest supported land-area overlap.

For ZIP codes that intersect more than one county, the full county relationship list remains available instead of silently collapsing the result to one county.

ZIP code to congressional district lookup

The result includes all supported 119th Congressional District intersections for the matching Census ZCTA and a primary district selected by the largest supported land-area overlap. This makes the Actor useful for congressional district lookup, district routing, civic-data enrichment, territory analysis, and jurisdiction matching.

The primary county and district fields are convenience mappings. Full relationship arrays stay available for multi-county or multi-district ZCTAs.

ZIP lookup API and batch input

Single lookup is the default. For bulk work, paste one ZIP code per line, up to 10,000 values. Normalized duplicates reuse the first completed lookup and are not charged twice in the same run.

Structured Dataset output can be consumed directly from Apify or through the Dataset API. Optional Census tract intersections are available when deeper geography detail is required.

Quick start

1. Paste a ZIP code such as 90210.
2. Click Start.
3. Read the county, county FIPS, and district fields in the Dataset overview.
4. Open the full row only when you need every relationship or source detail.

Important Census ZCTA scope

This Actor uses U.S. Census ZIP Code Tabulation Area (ZCTA) statistical geography. A ZCTA is not the exact USPS delivery boundary for a ZIP Code, and some USPS ZIP Codes do not have a matching ZCTA. A NOT_FOUND result means the packaged Census relationship data has no matching ZCTA; it is not a postal-address validity judgment.

Billing policy

A completed SUCCESS lookup or confirmed ZCTA NOT_FOUND lookup is one completed event. Invalid input is not a completed billable lookup. Duplicate normalized values within the same run reuse the first result and are not charged a second time.

Data source and independence

The packaged snapshot is built from published U.S. Census Bureau relationship files and runs offline after deployment, so normal lookups do not depend on a live government API, browser session, proxy, or login.

This is an independent data tool. It is not affiliated with, endorsed by, or operated by the U.S. Census Bureau or USPS. Source references are included in each result.