Based on the long-distance railcars of the VT 08⁵ series, the Bundesbahn had the railcars of the VT 12⁵ series manufactured for intercity services from 1953. Here, too, the multiple units were initially formed from a motor car, a trailer and a control car. Luggage and mail compartments were also accommodated in the motor cars, but the dining compartment was omitted. The carriages carried third and second class, which had been first and second class since the class reform in 1956. Oil-fired heating was no longer used in each individual car, but a central, heating system with water as transport medium. Some of the control cars came from VT 08⁵ control cars that were converted in 1957.

A total of twelve motor cars, 13 trailers and four control cars were built, five more control cars were added through conversion. They were also used on ferry services to Denmark, for which the floor had to be raised by 50 mm. With increasing electrification, the vehicles were only used in regional transport. In order to improve acceleration, two motor cars and one trailer were often used. From 1968 they were designated as class 612, but were increasingly replaced by other vehicles. These were mostly either locomotive-hauled trains with the class 218 or the railcars of the classes 614 and 624. After the last trains retired in 1985, only two motor cars and two trailers remained. These were combined into one train in 1988 and have been used as the “Stuttgarter Rössle” for excursions ever since. After a lengthy shutdown since 2008 and renewed refurbishment, it has been operational again since 2020.