Oklahoma Area Codes

About Area Codes in Oklahoma

Oklahoma (OK) is the The Sooner State, located in the South region of the United States. With a 2023 population of 4,059,394 residents, Oklahoma is served by 4 active area codes. The state capital is Oklahoma City and the largest city is Oklahoma City.Oklahoma's official motto is "Labor omnia vincit."

Area code assignments in Oklahoma follow the North American Numbering Plan (NANP), which has been in effect since 1947. As the state's population and demand for phone numbers grew — driven by the rise of cell phones, fax machines, pagers, and VoIP lines — regulators either split existing area codes geographically or added overlay codes that share the same territory. That's why Oklahoma now has 4 codes: 405, 539, 580, 918.

When you receive a call from a Oklahoma number, the area code tells you only where the number was originally assigned. Because of Local Number Portability (LNP), which took effect in 2003, callers can keep their phone numbers even when moving across state lines. So while a 405 number was once assigned in Oklahoma, the person calling you could be anywhere in the US today.

Time zones in Oklahoma

Oklahoma observes the Central time zone. Daylight Saving Time is observed from the second Sunday in March through the first Sunday in November, when clocks shift forward by one hour. When you call a Oklahoma number from outside the state, double-check the local time above each area code detail page to avoid calling at unreasonable hours.

Phone number format in Oklahoma

All Oklahoma phone numbers follow the standard 10-digit NANP format: (NPA) NXX-XXXX. For local calls within Oklahoma, you typically need to dial the full 10-digit number — even for calls within the same area code — because of mandatory 10-digit dialing imposed by the FCC for areas with overlay codes (most of Oklahoma's territory). For long-distance calls within the NANP, dial 1 + area code + 7-digit number.

Frequently asked questions about Oklahoma area codes

How many area codes does Oklahoma have?

Oklahoma currently has 4 active area codes: 405, 539, 580, 918.

What is Oklahoma's original area code?

The oldest area code(s) in Oklahoma were assigned in 1947 as part of the original 86 NANP codes. These legacy codes typically covered the entire state at first, then were split as demand grew.

What time zone is Oklahoma in?

Oklahoma is in the Central time zone.

Will Oklahoma get more area codes?

As Oklahoma's population and number demand grow, NANPA may assign additional overlay codes. When the current codes run out of available prefixes, regulators announce public hearings and propose new codes. The AreaCodeCentral team tracks these announcements and updates the directory within 24 hours of any new code activation.