Get Ready, Houston: Introducing Area Code 621!

Posted on
Nov 3, 2023
ATSI Content Team
ATSI Content Team
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The North American Numbering Plan (NANP) uses area codes 281, 346, 713, and 832 to create an overlay complex for the Houston, Texas metropolitan area. The Public Utility Commission of Texas (PUCT) has recently approved the introduction of the additional area code 621 in the near future. Its purpose is to accommodate the growing population in the greater Houston area.


Texas was originally divided into four numbering plan areas (NPAs) when the NANP was established in 1947. Each NPA roughly covered one of the state’s four quadrants, with area code 713 assigned to southeastern Texas, from the Sabine River to the Brazos Valley. This NPA was divided on March 19, 1983, to reflect the population growth in this area, especially in the south. The southern Houston area retained area code 713, while the northern, eastern, and western areas were assigned to area code 409.

The PUCT split area code 713 again on November 2, 1996, with most of this area switching to area code 281. The dividing line between the two area codes roughly corresponded to Beltway 8, with most of the area inside the beltway retaining area code 713, and area code 281 serving the area outside the beltway. However, all cellphone customers in the Houston area retained area code 713.

The PUCT originally intended this split as a long-term solution, but the growing demand for mobile telephone services in Houston required additional area codes within two years for both the 281 and 713 area codes. The NANP removed the boundary between these two area codes on January 16, 1999, while also adding area code 832 to this entire region. The resulting NPA required ten-digit dialing of all calls for the Houston area.

The PUCT announced the addition of area code 346 to the Houston NPA on May 9, 2013, which went into effect on July 1, 2014. The new area code increased the total number of phone numbers available in the Houston area to over 31 million, which had about eight million people at that time.

Adding the 621 Area Code

The PUCT performed a projection in 2022 that predicts that the Houston area will exhaust its supply of phone numbers for the 281, 346, 713, and 832 area codes by late 2025. The PUCT will therefore need to add a fifth area code by that time, resulting in the reservation of area code 621 as an additional overlay code for the Houston area. As of 2023, PUCT estimates that the addition of the new area code will meet the numbering requirements of the Houston area for the next nine years.

Telecommunication service providers will receive new numbers from area code 621 once all the numbers for the existing four area codes are assigned. PUCT doesn’t expect the addition of the 621 area code to impact existing phone numbers since this area already has multiple area codes. As a result, residents are used to dialing ten digits to make local calls.

Texas Governor Greg Abbott has stated that the Houston population continues to grow due to the freedom and opportunities Texas offers, which can’t be found anywhere else in the world. He added that the new area code illustrates the economic strength of the greater Houston area. Governor Abbott also thanked PUCT for taking the steps needed to improve the telephone infrastructure in Texas, allowing it to meet the growing demands of that state.


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Topics: Business Phone Systems, Business Communications Systems