US Area codes

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General Info

How many area codes are within the US? Well, There are 326 geographic area codes within the country and you will find detailed information on each of them, on this page. These area codes are used to make phone calls to specific geographic locations( in the case of local number area codes ), and they can also help identify where a call is coming from.

All area codes in the US are managed by the North American Numbering Plan Administration, or NANPA. This organization works with the Federal Communications Commission to assign and maintain North American area codes.

The US is broken down into several regional numbering plan areas, or NPA's. Each NPA is then divided into smaller prefixes that make up the individual area codes - you can look up area codes on our website. Most area codes are related to a particular geographic location, but some of them, for example, toll-free codes, have more general meanings.

Phone Number Format

The phone number format is regulated by the North American Numbering Plan Administration (NANPA). Every phone number within the US follows the following pattern:

+1 201 345 7890 , where:

+1 is the country code for the US
201 is the area code
345 is the prefix
7890 is the subscriber code

While the area code gives you information on the geographic area used by a given phone number, the prefix might give a more precise location as well as the name of the operating company for that phone number.

Country Code

Country codes are used to identify a specific country when making a phone call. Every country has its own unique country code, which is generally made up of a few digits and is typically preceded by a plus sign (+).

For example, the US country code is +1. When making a call from the US to another country, you would dial the country code before the full phone number.

These codes are also used when sending text messages. Understanding country codes is essential for anyone who needs to make international calls or send texts abroad. Without the country codes, these tasks would be impossible.

Area Code

Area codes are the three-digit numbers that appear before the local number on a US phone number, they are a vital tool for organizing phone numbers. They are used to identify a geographical area and are used to make sure calls are routed correctly.

This system helps keep numbers organized and makes it easier to call people in other states or cities. Every area code is unique, which means that when you dial a number in a different area code, you are calling a different area. Area codes are also used to identify different types of services, such as toll-free numbers, government offices, or mobile phones.

Geographical area codes also help provide an extra layer of security for businesses, as they can use a unique area code to differentiate themselves from competitors. For example, companies located in different states can use different area codes for their business numbers, making it easier to identify who is calling.

Do you know that clients are more eager to pick up on local phone numbers? Knowing the importance of area codes is especially important if you're running a business or relying on customers to call you. It's important to know what area code you're calling, as this will ensure you're connected to the right place. Without knowing your area code, you could end up calling the wrong person or place.


The central office code. or the prefix is the second set of three digits in a US phone number. This code is used to identify a specific telephone switch.

The switch is responsible for routing the call to the appropriate destination, it is operated by a specific telephone company and is assigned to a specific rate center.  

A rate center is an area of the country that is assigned to a specific rate plan. This rate plan determines the cost of the call. The rate center is determined by the area code and central office code.

When dialing a US phone number, it is important to include the area code and the central office code. This is necessary for routing the call to its proper destination. The area code and the central office code should not be confused with the line number, which is the last set of four digits in the phone number.

Subscriber Code

The subscriber code is the last four digits of a local phone number and is used to identify the individual phone line. It is also referred to as the line number or extension.

The subscriber code is a unique identifier for each phone line and helps the telephone company to track the usage of the line.

The subscriber line is used to identify the line and its associated features, such as call forwarding, voicemail, caller ID, and other services. It is also used to bill customers for their phone service. When customers receive their phone bill, the subscriber code is included on it to help identify the line.

The subscriber code is important for telecommunication companies, as it helps them keep track of their customer's phone lines and usage. It also helps them to troubleshoot any problems that may arise with the phone line.