636
Area code
Statusin service
Introduced1999-05-22
JurisdictionMO, US
Local dialing7D
Time zoneCentral
Last verified2026-09-17
Utilization 57.6% of assignable prefixes assigned
As of 09/17/2026
0%456 of ~792 assignable NXX values (200–999 excl. N11)100%
Prefix-level assignment does not equal number-level exhaustion; thousands-block pooling extends capacity. First assignment on record 2001-01-18, most recent 2026-09-10.
Area codes serve rate-center geographies, not municipal boundaries. “MO” identifies the jurisdiction, not an exact city footprint.
Top assignees
Ranked by assigned prefixes · initial assignee ≠ current carrier| Rank | Assignee | Prefixes | Share |
|---|---|---|---|
| 01 | SOUTHWESTERN BELL | 110 | 24.1% |
| 02 | BRIGHTSPEED OF MISSOURI, LLC | 49 | 10.7% |
| 03 | ONVOY, LLC - MO | 36 | 7.9% |
| 04 | T-MOBILE USA, INC. | 35 | 7.7% |
| 05 | NEW CINGULAR WIRELESS PCS, LLC - IL | 29 | 6.4% |
| 06 | LEVEL 3 COMMUNICATIONS, LLC - MO | 29 | 6.4% |
| 07 | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MO | 28 | 6.1% |
| 08 | PAETEC ITEL, LLC | 25 | 5.5% |
| 09 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO | 20 | 4.4% |
| 10 | CHARTER IP ENABLED SERVICES, LLC | 18 | 3.9% |
Important: these are initial assignees from NANPA CO-code records — the carrier a prefix was originally assigned to. Because of number portability, the current serving carrier of any individual number may differ.
Change history
Recorded events for this NPA- 1999-05-22Area code 636 entered service (created from 314).
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 1999-02-23 | PL-165 ↗ | Geographic Split of 314 (Missouri) Numbering Plan Area (NPA) |