Cities in area code 636

46 localities · NANPA data, current as of July 28, 2026.

These are the cities and communities covered by 636 in Missouri. "Covered" means the locality is a rate center holding 636 prefixes; the largest are Saint Charles, Chesterfield, Harvester.

Saint Charles, Chesterfield, Harvester, Manchester, O'fallon, Fenton, Festus Crystal City and Saint Peters hold the largest prefix inventories; and 37 smaller communities down to single-prefix localities. Each locality below links to its rate-center page with the full prefix list.

45 of the localities fall within FCC top-100 metropolitan statistical areas; the rest are smaller communities.

All of the code's territory keeps Central time.

Remember that people keep numbers when they relocate, so a 636 number is a where-it-was-issued fact, not a where-they-are fact.

FAQ

What is the biggest city in area code 636?

Saint Charles holds the most active prefixes (43), making it the code's largest numbering locality.

How many places does 636 cover?

46 rate centers in Missouri hold active 636 prefixes, from Saint Charles down to communities with a single prefix.

Does a 636 number guarantee the caller lives in one of these places?

No — the tables show where number blocks were issued. Porting and VoIP let people keep or acquire numbers anywhere.