Every active US telephone area code mapped to its state, primary city or region, and timezone. Use this dataset for phone number validation, geographic caller identification, fraud detection, and building intelligent phone input forms that auto-detect location from area codes.
Pro tip: Load this dataset as a hash map keyed by area code for instant caller location lookups — extracting the first three digits of any US phone number gives you the geographic origin without needing an external API.
Select which columns to include in your download.
About the US Area Codes Dataset
This dataset contains every active telephone area code in the North American Numbering Plan (NANP) that serves the United States, including US territories. Each record maps a three-digit area code to its state, the primary city or metropolitan region it serves, and the IANA timezone for the area. The data is compiled from the North American Numbering Plan Administration (NANPA) assignments and verified against current FCC records.
Common Use Cases
Area code data serves as a lightweight geographic signal embedded in every US phone number:
- Phone validation: Verify that a phone number begins with a valid, active area code before accepting it in your application, catching typos and invalid entries early.
- Caller ID enrichment: Display the geographic origin of incoming calls by looking up the area code, providing users with city and state information before they answer.
- Fraud detection: Flag phone numbers where the area code does not match the expected geographic region of a transaction, adding a signal to your fraud scoring model.
- Regional routing: Route customer support calls to the nearest call center by matching the caller's area code to a regional timezone or state assignment.
Column Reference
The dataset includes the following columns for each area code:
- area_code — The three-digit telephone area code (e.g.
212,310,512). - state — The two-letter state abbreviation where the area code is assigned (e.g.
NY,CA,TX). - city — The primary city or metropolitan region served by the area code. For overlay codes, this shows the major city in the overlay region.
- timezone — The IANA timezone identifier for the area code's geographic region (e.g.
America/New_York).
Overlay Area Codes
Many US regions now have multiple area codes serving the same geographic area, known as overlay codes. When a region exhausts its original area code assignments, NANPA introduces an overlay code that covers the same territory. This means area code alone does not always uniquely identify a specific sub-region within a state. Both the original and overlay codes will appear in this dataset with the same city and state, reflecting their shared geographic coverage. For precise location lookups, combine the area code with the exchange (next three digits) for finer granularity.
Integration and Performance Tips
For real-time applications like caller ID or phone input validation, load this dataset into an in-memory hash map or dictionary keyed by area code. With only a few hundred entries, the entire dataset fits comfortably in memory and provides constant-time lookups. The JSON format is ideal for this purpose — parse it once at application startup and query it for every phone number interaction. For database-backed applications, the SQL export creates a compact table that can be JOINed against call logs or customer records to enrich them with geographic metadata without requiring an external geocoding service.