Below is a table of bus companies managed by STEO providing a bus code and contact line for each:
| Bus Code | Contractor Name | Telephone |
| FS | 417 Bus Line Ltd. | 613-764-2192 |
| AR | A&R Enterprises | 613-930-6737 |
| BB | Barr Bus Lines Ltd. | 613-624-5260 |
| BC | Brockville City Bus Lines Ltd. | 613-342-4848 |
| CM | C. Martin’s Bus Service Ltd. | 1-844-335-7545 |
| CB | Clark Bus and Marina Ltd. | 613-382-0016 |
| DE | Delaney Bus Lines Ltd. | 613-346-2511 |
| EV | Evans Bus Lines Ltd. | 613-346-2278 |
| FI | First Student Canada – Cornwall Division | 613-938-8000 |
| FI | First Student Canada – Prescott Division | 613-925-2966 |
| GM | Gerald Mulville | 613-273-5229 |
| HE | Healey Transportation Ltd. | 613-283-3518 |
| HI | Highland Bus Service | 613-259-3106 |
| HB | R.A. Howard Bus Service Ltd. & D. Howard Bus Service | 613-924-2720 |
| JM | Jeff Morrison | 613-812-0471 |
| LA | Lalonde Bus Lines Inc. | 613-487-2230 |
| LN | Lannin’s Garage | 613-448-2361 |
| LE | Leduc Bus Lines Ltd. | 613-446-0606 |
| MJ | M.J. Waldroff Ltd. | 613-346-5708 |
| PR | Premier Bus Lines Inc. | 613-253-8863 |
| QU | Quesnel Bus Lines Ltd. – Hawkesbury | 613-632-7809 |
| QU | Quesnel Bus Lines Ltd. – Athens and Perth | 613-326-0707 |
| RC | R&C Cuerrier Enterprise Ltd. | 613-632-4004 |
| RT | Reliable Transportation | 613-264-1000 |
| RO | Roxborough Bus Lines Ltd. – Alexandria | 613-525-1443 |
| RO | Roxborough Bus Lines Ltd. – Clarence/Rockland | 613-488-2337 |
| RO | Roxborough Bus Lines Ltd. – Maxville | 613-538-2461 |
| VL | Valley Bus lines Ltd. | 613-258-4022 |
| WH | Whitteker Bus Lines | 613-652-2467 |
| WU | Wubs Transit | 613-774-6618 |
