Unfortunately there are very few taxis in Berlin that can transport wheelchairs. Trips should therefore be booked early. A list of wheelchair taxi providers can be found here:http://rollstuhltaxi-berlin.de/category/taxis/
Of course any taxi can be used if the wheelchair user can transfer himself or herself from the wheelchair and the wheelchair fits in the trunk. Taxi Berlin can be reached at 030 – 202020 to order a minivan or a station wagen – inform them that you are traveling with a wheelchair.
Or you can order a minivan taxi directly at mytaxi.de.
In addition there are several shuttle services in Berlin for people with disabilities. A list of providers can be found here: http://rollstuhltaxi-berlin.de/category/fahrdienste/
People living in Berlin, who fulfill certain requirements, can apply for a special card for the far less expensive shuttle service SFD (Sonderfahrdienst). More information can be found here:
http://rollstuhltaxi-berlin.de/unterstuetzung-vom-land-berlin/