Area Code Guides
In-depth reference articles about North American area codes — history, geography, how splits and overlays work, and more.
Area Code 808: Hawaii's Single Area Code Explained
The entire Hawaiian island chain — from Kauai to the Big Island — is served by a single area code. Here's the story of 808 and why the islands have never needed a second one.
Area Code 907: Why Alaska Has Just One Area Code
Alaska is the largest US state by area but has only one area code. How has 907 managed to serve a state larger than Texas, California, and Montana combined?
What Is an Overlay Area Code?
Overlay area codes let two or more area codes serve the same geographic territory. They're controversial but now widespread. Here's exactly how they work.
Area Code 212: The Story Behind New York's Original Number
Area code 212 is one of the most recognized phone numbers in the world. Here's the full history of New York City's original area code and how it has changed over the decades.
The North American Numbering Plan: How Area Codes Work
Every phone number in the US, Canada, and 18 other countries follows the same plan. Here's how the North American Numbering Plan came to be and why it still matters.