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Where Is 636 Area Code?

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Database Updated: August 8, 2025
Missouri Phone Number Lookups
Where Is 636 Area Code?

Where is Area Code 636?

Area code 636 is located in the state of Missouri. It serves several major cities, counties, and regions, providing essential telecommunication services to residents and businesses. The area code covers:

  • St. Charles County
  • Jefferson County
  • Franklin County
  • Warren County
  • Lincoln County
  • St. Louis County
  • Montgomery County
  • Cities such as St. Charles, St. Peters, O'Fallon, and Chesterfield

For more information about the regions covered by area code 636, visit the Missouri Public Service Commission.

Missouri Public Service Commission
200 Madison Street, PO Box 360, Jefferson City, MO 65102-0360
Utility Consumer Hotline: (800)-392-4211
pscinfo@psc.mo.gov

What time zone is 636 area code in the USA?

The 636 area code is situated in the Central Time Zone (CT) of the United States. This time zone observes Daylight Saving Time, shifting from Central Standard Time (CST) to Central Daylight Time (CDT) during the warmer months. For accurate timekeeping, refer to the National Institute of Standards and Technology.

History of the 636 Area Code

The 636 area code was established in 1999 as a result of a split from the 314 area code. This change was necessitated by the growing demand for new telephone numbers in the region, driven by population growth and the proliferation of mobile devices. The split allowed for a more efficient allocation of numbers to meet the needs of residents and businesses. For more details on the history and administration of area codes, consult the North American Numbering Plan Administrator (NANPA).

NANPA Mailing Address
One Tower Center Boulevard
Suite 800
East Brunswick, NJ 08816

NANPA Customer Support
Tel: 1-866-623-2282
Email: support@nanpa.com
Fax: 571-363-3838

How Many People Use the 636 Area Code?

The population served by the 636 area code encompasses several counties and cities in Missouri. The U.S. Census Bureau provides detailed demographic data for these regions, which can be accessed through their website.

U.S. Census Bureau
4600 Silver Hill Road, Washington, DC 20233
Tel: 301-763-INFO (4636) or 800-923-8282

Is the 636 Area Code Toll-Free?

The 636 area code is a geographic area code, not a toll-free number. It is designated for specific regions within Missouri and is used for local calls within its coverage area. Toll-free numbers in the United States typically begin with prefixes such as 800, 888, 877, 866, 855, 844, and 833. For more information on toll-free numbers and their operation, visit the Federal Communications Commission.

Federal Communications Commission
45 L Street NE, Washington, DC 20554
Tel: 1-888-CALL FCC (225-5322)
https://www.fcc.gov/

Missouri Phone Numbers
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