| 203 | Connecticut (Bridgeport, New Haven, Waterbury and southwestern Connecticut; proposed overlay with 475) More information at: Area Code 203 Phone Number Blocks |
| 475 | Connecticut (Bridgeport, New Haven, Waterbury and southwestern Connecticut, overlays with 203). More information at: Area Code 475 Phone Number Blocks |
| 860 | Connecticut (Bristol, Hartford, Norwich and northern and eastern Connecticut) More information at: Area Code 860 Phone Number Blocks |
| 959 | Connecticut (Bristol, Hartford, Norwich and northern and eastern Connecticut, overlays with 860) More information at: Area Code 959 Phone Number Blocks |
