Public Utility Commission of Texas

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Texas Area Codes

Area Codes Frequently Asked Questions

Who has authority over area codes?

The Federal Communications Commission (FCC) has jurisdiction over telephone number administration in the United States. Area codes do not cross state boundaries, so each state has the authority to decide when and in what form to introduce new area codes. In Texas, this authority rests with the Public Utility Commission of Texas (PUC).

Who decides when a new area code is needed?

The North American Numbering Plan Administration (NANPA), currently administered by Somos Inc., studies historic growth, makes projections for future growth, and notifies the PUC when a new area code is needed. The affected area code is described as being near "exhaust." The PUC is notified three years prior to exhaust.

What happens after NANPA notifies the PUC a new area code is needed?

A public meeting may occur in the region in which a new area code is needed in order to educate customers and receive public comments. If a region already has more than one area code, a public hearing may not be needed because customers will not need to change their current dialing methods; however, a public comment period will still take place. The PUC will issue an order deciding how a new area code will be added. The area code may be implemented as an additional area code for the region (an "overlay" to an existing area code), or the region may be split and each region assigned a single area code (a "geographic split"). The difference between an overlay and a geographic split is explained below.

The PUC allows time for network preparation and customer education for a new area code. In regions where 10 digit dialing is being introduced, the PUC may require a permissive dialing period that allows customers to dial 7 or 10 digits. These steps typically take six months. After the permissive dialing period ends, a period of mandatory dialing for the existing area code begins where all customers must dial all 10 digits of the existing area, which also typically occurs for six months. After conclusion of mandatory dialing, phone numbers from the new area code will be assigned to service providers and 10 digit dialing is required for both the new and existing area codes.

Can I comment on a proposed new area code?

Yes, the PUC welcomes your comments. You can comment at the public meeting if one is held, send your written comments to the PUC, or email

Who decides what the new area code will be?

NANPA assigns new area codes for the entire nation. Following a PUC decision on how a new area code will be added, NANPA determines the new area code and informs the PUC. The PUC announces the new area code to the public.

Why are new area codes needed?

New area codes are needed for the increasing number of phone numbers in a region, for such things as cellphones and phones for homes and businesses.

How many numbers are in an area code?

Normal phone numbers are identified as NXX-XXXX (e.g. 555-1234). N acts as any digit 2-9 and X is any digit 0-9. Each area code has 792 prefixes or "NXX" codes. Each NXX has 10,000 possible numbers. Therefore, theoretically, there are 7,920,000 telephone numbers per area code. In reality, since phone companies need test numbers and codes for other operational reasons, not all of the telephone numbers can be utilized by customers.

What is the difference between an "overlay" and a "geographic split"?

Geographic Split

A geographic region covered by the area code is divided. One region keeps the existing area code. The other region is assigned a new area code.


The area code provides a geographic identity, and you keep seven-digit dialing for local calls.


It takes time to alert friends and businesses if you get a new phone number because of the new area code, and it costs money to change the phone number on checks, mailing labels, business supplies, and advertising.


An overlay places a new area code over the same geographic region or over a portion of that region in what is called a concentrated overlay. This creates two or more area codes in the same region. New customers are assigned the new code, while existing customers keep their existing code and phone numbers.


You keep your area code, and you do not have to change advertising and other printed items.


You must dial 10 digits to place a local call, and a single residence or business could have two different area codes for different lines.

Does an area code change affect long distance rates?

No. Calls that were local before the change will remain local calls. For a geographic split, you may have to dial 10 digits to reach certain cities in your local area, but it is still a local call.

With an overlay, you must remember to dial the area code along with your original seven-digit number, but you are charged as you were before the overlay. You are still making a local call.

Does a new area code affect my local phone bill?

No, your phone bill stays the same.

Are 9-1-1 calls affected?

No, the emergency telephone system serving you will be reprogrammed.

How can I get a specific phone number?

The PUC does not know if specific phone numbers are available. You would need to contact the service providers for your area to see if anyone has been assigned that phone number.

Who can I call if I have more questions about a new area code?

Call your phone company. If your questions are not answered, email