Emergency crews were called to the collision which happened in Ox Leys Road near Wishaw, off the A38 near Sutton Coldfield, at 7.15pm on Saturday.
West Midlands Fire Service said its crews used specialist equipment to help six of the seven passengers in the private hire taxi, some of whom suffered serious injuries. A seventh passenger, who suffered minor injuries, was able to get out of the vehicle on their own before crews arrived at the scene.
"Their injuries, some minor, some more serious, were triaged and the passengers were given oxygen therapy on scene by our crews, prior to the arrival of West Midlands Ambulance Service. An air ambulance with trauma doctors also attended the incident," the brigade stated.
The car driver suffered limited injuries.
All of the casualties were taken to various hospitals by land ambulances and the air ambulance.
The incident is being investigated by West Midlands Police.
Fire crews from Sutton Coldfield and Aston attended the incident with Ladywood's response vehicle. The crews left the scene at about 8.50pm.