**Zip-Codes API** is a production REST API for US and Canadian postal-code data — address validation and standardization, radius search, point-to-point distance, autocomplete, and demographic enrichment — built for teams that need clean addresses, accurate territories, and Census-grade demographic context without operating a separate geocoding stack and a separate Census data pipeline.
It's the API rebuild from Zip-Codes.com, a brand with 23 years of postal-data operating heritage. US ZIP boundaries and address data are refreshed monthly. The underlying data and matching engines have been hand-corrected for boundary edge cases, military and Puerto Rico addressing, and ZIP+4 ambiguity for more than a decade; the v2 API generally became available in 2026, but the data quality behind it is not new.
**Who uses it.** E-commerce checkout and operations teams losing revenue to failed deliveries from typo-ridden addresses. RevOps and CRM admins (Salesforce, HubSpot, Pipedrive) watching dirty lead data break territory routing. Store-locator and service-area product teams whose "crow-flies" radius results include places customers can't actually reach. Real estate, proptech, and market-research teams that need ZIP-level demographics across history without standing up their own Census ETL. Logistics and dispatch teams managing distance and addressing across both the US and Canada under a single contract.
**The endpoint surface.** Six endpoints, one consistent contract:
• /v2/address` — Free-form address validation and standardization with ZIP+4 append. Returns parsed components (primary number, street, secondary unit, city, state, ZIP+4), confidence flags, and an extensive taxonomy of reason codes that surface ambiguity honestly rather than silently guessing. Handles US addresses including Puerto Rico (urbanization keys), military (APO/FPO/DPO), suite/apartment parsing, PO boxes with route-and-box-range validation, directional disambiguation, and more.
• /v2/zip — Full postal-code lookup with opt-in enrichments. A single `code` parameter accepts US ZIP, US ZIP+4, Canadian FSA, full Canadian postal code, or `lat,lon` coordinates. Returns core postal data (city, state/province, county, classification, location, parent code, and detailed ZIP+4 street records when supplied) plus any combination of opt-in enrichments: ACS demographics (any of 14 years × 4 standard Census profiles), Census tract / block-group / CBSA / urbanized-area identifiers, congressional district, state legislative district, school district, Medicare/CMS data, and timezone.
• /v2/radius — ZIPs and postal codes within range of a center point. Two modes: `centroid` (haversine, fast, up to 500 miles) and `spatial` (true polygon intersection, up to 250 miles, with per-result percent-inside). Supports `auto` and `auto-commute` radius modes — the API computes an appropriate radius based on each center's population density or commute-flow pattern. Optional ACS aggregation across matched ZIPs, weighted by polygon overlap in spatial mode.
• `/v2/suggest` — Multi-entity autocomplete: cities, counties, metropolitan areas, states/provinces, FSAs, ZIPs, school districts, USPS cities. Sub-millisecond response from an in-memory trie with SQL fallback. Optional proximity bias from caller IP (or a `lat,lon`, postal code, or state hint).
• /v2/quick-zip — Lightweight 1-credit validation for high-volume "is this code valid, what country is it" checks. Same input flexibility as `/v2/zip`, minimal output.
• /v2/distance — Point-to-point distance (miles and kilometers) and great-circle bearing between any two postal references. Accepts ZIP, ZIP+4, FSA, postal code, or coordinates on either side. Timezone is always included.
All endpoints support GET and POST. The five primary endpoints have batch variants (up to 100 inputs per request; subscription required for batch).
**Five differentiators vs. the address-verification and geocoding peer group:**
1. **Unified US + Canada in a single API and single contract.** Most direct competitors require separate products or contracts per country, or are US-only. Canadian FSA and full 6-character postal coverage are in-line, not bolted on.
2. **True spatial polygon radius search.** Most ZIP APIs do centroid-haversine only ("how far apart are these two centroids?"). We also support true polygon intersection with computed percent-inside per match — the right tool for service-area coverage, territory assignment, delivery-zone compliance, and any case where a ZIP partially inside the radius needs to be weighted accordingly.
3. **Demographic depth without an enterprise contract.** 542 ACS canonical fields across 14 years (2011–2024) spanning all four standard Census profiles — demographic, social, economic, housing. Available per-lookup or aggregated across radius matches, weighted by polygon overlap in spatial mode. Historical depth like this is normally found in enterprise-only data products at 5-figure annual contracts.
4. **Pricing transparency with a real free tier.** $49 / $149 / $499 monthly plans published. 2,500 requests per day free, no credit card required, no expiry. One-time credit packs from 25K ($19) up to 2M ($799) for pay-as-you-go workloads. No "contact sales" wall on any of the published plans.
5. **Single-endpoint simplicity.** Every endpoint accepts US ZIP, US ZIP+4, Canadian FSA, Canadian postal code, or `lat,lon` coordinates interchangeably. No country-detection logic, no per-input-type routing on the client side — one parameter, one parser, one consistent response envelope.
**On boundary data and geographic context.** Every ZIP and postal-code lookup can optionally return the political and educational geography that contains it: congressional district, state legislative district (upper and lower chamber), school district, Census tract, block group, place, and metropolitan/micropolitan statistical area. For radius queries in spatial mode, each match also carries the percentage of that ZIP's area falling inside the search radius — useful for accurate territory assignment, service-area coverage, and compliance reporting. The underlying boundary data is licensed and refreshed on a maintained schedule; clients receive the *result* of the spatial computation — names, codes, FIPS identifiers, overlap percentages, areas in square miles — rather than the raw polygon geometry. That keeps responses small, fast, and immediately usable inside a CRM record, an analytics warehouse, or a checkout form. For teams that previously combined a geocoder with a separate Census ETL or shapefile pipeline, the API collapses two systems and two maintenance burdens into one call.
**Pricing and credits.**
• Free — 2,500 requests/day, no credit card, no expiry. 60 requests/minute.
• Developer — $49/month, 100K credits/month, 300 req/min.
• Professional — $149/month, 350K credits/month, 300 req/min.
• Business — $499/month, 1.5M credits/month, 600 req/min.
• One-time credit packs — 25K ($19), 65K ($49), 150K ($99), 300K ($179), 2M ($799). No expiry; stack with free or subscription credits.
The credit formula is multiplicative: each additional enrichment adds 1 to a per-call multiplier. A base ZIP lookup with three enrichments costs 4 credits; without enrichments it costs 1. Customers pay only for the depth they actually request.
**Operational specifics.** REST/JSON over HTTPS. API-key authentication via `X-Api-Key` header (or `?key=` query parameter for browser-side use cases where the header is awkward). CORS enabled (with optional per-key origin allowlist). Response compression (gzip/Brotli per Accept-Encoding). Per-item failure reporting in batch responses, so one bad input in a batch of 100 doesn't fail the entire request. Sliding-window rate limiting per tier. Sub-second 99th percentile on typical lookups. Comes with an OpenAPI 3 specification (api.zip-codes.com/v2/openapi.json) and a public Postman collection at api.zip-codes.com/postman for one-click workspace forking. Most teams replacing a basic ZIP-code API or augmenting an existing geocoder are integrated end-to-end in an afternoon.
**Trying it out.** Sign up at zip-codes.com/api for an API key (no credit card). The interactive playground at api.zip-codes.com/docs lets you exercise every endpoint with your own key or with the public demo key against a curated set of demo postal codes. The OpenAPI spec, Postman collection, and documentation are all publicly accessible without authentication.
**What it's not.** Zip-Codes API is focused on North American postal data. It does not provide international postal coverage outside US and Canada, free-form street-level geocoding outside the US, raw boundary geometry downloads, ETL/file-ingest workflows, or asynchronous job queues. Teams with those needs are better served by other categories of product.
Built and operated by the team behind Zip-Codes.com. For accurate postal data, refreshed monthly, with the demographic and geographic context already attached — through a modern API with published pricing and a real free tier.
Who Is the Company Behind Zip-Codes API?
