CallataGuidesGet a local business phone number in O'Fallon, MO
O'Fallon's area code, prefixes and carriers from NANPA records, and how to put a O'Fallon number in front of your customers.
- Area code
- 636
- Exchanges
- 24NANPA-assigned
- Carriers
- 11
- Population
- 95,355Census 2024 est.
Area codes in O'Fallon
O'Fallon city is a Census place in St. Charles County, Missouri, with an estimated 95,355 residents in 2024. All 24 exchanges NANPA lists for its rate center are in area code 636. O'Fallon is in the Central time zone.
According to NANPA's dialing-plan data, local calls within 636 are dialed as seven digits and toll calls as 1 plus ten digits.
| Area code | Exchanges here | Share | In service since | Overlay with | Time zone |
|---|---|---|---|---|---|
| 636 | 24 | 100% | 1999 | none | Central |
Source: NANPA utilized central office code file and NPA report, dated 10/01/2026.
O'Fallon exchanges by carrier
11 carriers hold the 24 exchanges assigned to O'Fallon's rate center. Brightspeed of Missouri, LLC has the most, with 8. 19 of them are pooled codes, which the holder shares with other carriers in blocks of 1,000 numbers. Holding a code means NANPA assigned that block of numbers to the carrier for this rate center; individual numbers may since have been ported elsewhere.
| Carrier (NANPA operating company) | Exchanges | Share |
|---|---|---|
| Brightspeed of Missouri, LLC | 8 | 33% |
| New Cingular Wireless PCS, LLC - Il | 4 | 17% |
| T-mobile USA, INC. | 3 | 13% |
| Charter Ip Enabled Services, LLC | 2 | 8.3% |
| Boost Subscriberco L.l.c. | 1 | 4.2% |
| Shelcomm | 1 | 4.2% |
| Paetec Itel, LLC | 1 | 4.2% |
| Level 3 Communications, LLC - Mo | 1 | 4.2% |
| Commio, LLC | 1 | 4.2% |
| Teleport Communications America, LLC - Mo | 1 | 4.2% |
| Ton80 Communications, LLC | 1 | 4.2% |
Carrier names are the operating company (OCN) names on NANPA's utilized central office code file dated 10/01/2026. A carrier holding a code may port numbers to other carriers.
Exchanges (NPA-NXX) assigned in O'Fallon
A prefix (NXX) is the three digits after the area code. Numbers starting with these prefixes are rated as local to O'Fallon. The earliest assignment date recorded in the file for these codes is 2001. 5 of the 24 were assigned in 2020 or later.
| Area code | Prefixes (NXX) |
|---|---|
| 636 | 240, 272, 281, 293, 294, 312, 339, 351, 379, 385, 409, 439, 470, 474, 515, 542, 544, 614, 630, 696, 849, 874, 978, 980 |
Source: NANPA utilized central office code file.
When O'Fallon's exchanges were assigned
The table groups O'Fallon's exchanges by the decade NANPA recorded them as assigned.
| Decade assigned | Exchanges | Share |
|---|---|---|
| 2000s | 5 | 31% |
| 2010s | 6 | 38% |
| 2020s | 5 | 31% |
Assignment dates as recorded in NANPA's utilized code file; codes without a recorded date are excluded.
How local numbers work in O'Fallon
Phone numbers are tied to a rate center, the local calling area used to decide whether a call is local or toll. O'Fallon's numbers are rated to the OFALLON rate center in NANPA's records. A business number from one of the prefixes above shows up on customers' phones as a O'Fallon number.
Keeping an existing O'Fallon number costs nothing on Callata, because porting is free; a new number depends on what carriers have open in 636 when you pick it.
Who does business near O'Fallon
O'Fallon is part of the St. Louis, MO-IL metro area, home to 2.8 million people in 2024. County Business Patterns counted 69,470 business establishments in the St. Louis, MO-IL metro area in 2023, employing 1,263,674 people. The largest sectors by establishment count are health care and social assistance (10,427), retail trade (8,095), and professional, scientific, and technical services (7,057).
| Industry | Establishments | Employees | Employees per establishment |
|---|---|---|---|
| Limited-service restaurants | 2,334 | 45,289 | 19.4 |
| Full-service restaurants | 2,019 | 49,930 | 24.7 |
| Agencies providing services for the elderly and persons with disabilities | 1,898 | 16,546 | 8.7 |
| Physician practices | 1,785 | 22,126 | 12.4 |
| Insurance agencies and brokerages | 1,509 | 7,839 | 5.2 |
| Law offices | 1,393 | 10,509 | 7.5 |
| Offices of real estate agents and brokers | 1,099 | 2,523 | 2.3 |
| Landscaping services | 1,092 | 7,504 | 6.9 |
Selected small-business industries (six-digit NAICS) covered by these guides. Source: Census County Business Patterns 2023.
Business phone service in O'Fallon
For $99 a month, Callata puts a team of up to 5 on one plan ($20 for each person after that): up to 3 local numbers, unlimited inbound calls, a pooled allowance of 1,500 outbound US and Canada minutes per user, browser and cell calling, voicemail transcription with urgency triage, recorded calls with AI summaries and business-hours routing, with E911 on every number.
Porting a number you already use in O'Fallon is free, and business texting is available once the carrier registration (10DLC) is approved; the registration carries a one-time $49 fee. Which specific numbers are open in a given area code depends on carrier inventory at the time you sign up.
AI agents are optional: an AI receptionist or scheduler can pick up when the team is busy or closed, take a message, send a text or email, or transfer the call. They draw on prepaid AI minutes ($0.25/minute), disclose that they are AI, and outbound AI calls require prior consent and are limited to 8am–9pm.
Per-seat phone plans multiply by headcount. For the rounded average establishment size in the St. Louis, MO-IL metro area, 18 users on RingCentral RingEX Core come to $540.00 a month and on Ooma Office Pro $449.10, at month-to-month list prices checked September 28, 2026. Callata comes to $359.00 a month for 18 users ($99 a month with 5 users included, then $20 per additional user), below both.
| Provider (plan) | Pricing basis | Per month | Per year |
|---|---|---|---|
| Callata (Callata Office) | $99 incl. 5 users, $20 per extra user | $359.00 | $4,308.00 |
| Quo (Starter) | $19.00 per user | $342.00 | $4,104.00 |
| Nextiva (Core) | $23.00 per user | $414.00 | $4,968.00 |
| Ooma (Office Pro) | $24.95 per user | $449.10 | $5,389.20 |
| Dialpad (Standard) | $27.00 per user | $486.00 | $5,832.00 |
| RingCentral (RingEX Core) | $30.00 per user | $540.00 | $6,480.00 |
Competitor prices are each vendor's published month-to-month list price per user for its lowest plan that includes business calling and texting, checked September 28, 2026: Quo Starter $19, Nextiva Core $23, Ooma Office Pro $24.95 (Essentials excludes texting; one-time $29.95 activation not included), Dialpad Standard $27, RingCentral RingEX Core $30 ($20 billed annually). Prices exclude taxes and fees and may change; annual contracts lower some competitors' prices.
Frequently asked questions
What area code is O'Fallon, MO?
636. All exchanges NANPA lists for O'Fallon are in 636.
How many phone companies have exchanges in O'Fallon?
11, holding 24 exchanges between them, according to NANPA's 10/01/2026 file.
Can I keep my existing O'Fallon business number?
Yes. Porting an existing number to Callata is free. Texting from it starts after carrier registration (10DLC), a one-time $49 fee.
How much is a business phone line in O'Fallon?
Callata is $99 a month with 5 users included, then $20 per additional user, with up to 3 local numbers; 18 users come to $359.00 a month. For comparison, 18 users on RingCentral RingEX Core list at $540.00 a month (checked September 28, 2026).