# Area Code Overlay

An Area Code Overlay is an area code that covers the same geographical space as another area code. In North America, each area code has a potential capacity of around 8 million unique phone numbers — 7,919,900, to be exact. Many area codes have exhausted all possible phone numbers, so one or more area codes are added to accommodate.

## An Area Code Overlay example

`212` is the original area code for New York City (Manhattan, to be exact). The overlays `646`, `917`, and `332` were added later as the need for phone numbers has grown past each code's maximum of 7,919,900 numbers. Here is a [full list of overlays in the North American Numbering Plan](https://en.wikipedia.org/wiki/List_of_area_code_overlays).

## Twilio local phone numbers

To check if Twilio has available phone numbers in your target area code, or in an overlay, use the [Console](https://www.twilio.com/console):

![Buy a number interface with options for country, number, and capabilities like Voice and SMS.](https://docs-resources.prod.twilio.com/e82009c127ce22e037d02c25ba02a6b8d73b5d62a33e2ad16b3865515736dce2.png)

In the above image, you can see a search for the area code `209`, for the general area around Stockton, CA. If you were searching for a San Francisco number, you could try 415 or the Area Code Overlay `628`. Availability will be detailed in the results, but Twilio very often will have numbers available from primary area codes and overlays.