Home › Connecticut › Old Greenwich
Old Greenwich, CT Area Codes
Old Greenwich, Connecticut (population 6,904) uses area codes 203 and 475.
Carriers with Old Greenwich numbers
13 prefixes are assigned to the Old Greenwich exchange: 0% mobile, 69% VoIP and cable, 31% landline.
| Carrier | Prefixes |
|---|---|
| Verizon Business (MCImetro) | 5 |
| Frontier | 3 |
| Onvoy (Sinch) | 2 |
| Cablevision Lightpath | 1 |
| AT&T (Teleport) | 1 |
| Fractel | 1 |
Area codes used in Old Greenwich
| Area code | Prefixes serving Old Greenwich | Main carriers in this code |
|---|---|---|
| 203 | 9 | Frontier, Verizon Wireless, AT&T Mobility |
| 475 | 4 | Onvoy (Sinch), Verizon Wireless, T-Mobile |
Old Greenwich phone number prefixes
Numbers starting with these first six digits were originally assigned to the Old Greenwich exchange.
203-277Verizon Business (MCImetro)203-344Cablevision Lightpath203-369Verizon Business (MCImetro)203-409AT&T (Teleport)203-637Frontier203-698Frontier203-827Verizon Business (MCImetro)203-986Verizon Business (MCImetro)203-990Verizon Business (MCImetro)475-249Frontier475-340Onvoy (Sinch)475-465Onvoy (Sinch)475-946Fractel
Nearby cities in area code 203
- Bridgeport
- Stamford
- New Haven
- Waterbury
- Norwalk
- Danbury
- Meriden
- West Haven
- Milford
- Shelton
- Naugatuck
- East Haven
Questions
- What is the area code for Old Greenwich, CT?
- Old Greenwich uses 2 area codes: 203 and 475. They overlay each other, so all of them cover the whole city and you dial 10 digits for local calls.
- What time zone is Old Greenwich in?
- Old Greenwich is in the Eastern time zone.