The main sphere of operations for the T 12 was the Berlin area, where it worked the city network, ring railway, and suburban lines as a predecessor of electric S-Bahn traction.

The engines had to be capable of rapid acceleration when in charge of compartment coach trains in order to achieve acceptable journey times, due to the short distances between stations on some routes.

After the electrification of much of the S-Bahn network between 1924 and 1929, the locomotives were switched to normal passenger and goods train services and shunting.

[4] Locomotive 74 498 remained in Austria after the end of the Second World War where the ÖBB classed it as 674.498 in its tractive fleet.

In 1950 the East German Deutsche Reichsbahn took over four of the locomotives bought by the Halberstadt-Blankenburg Railway, numbering them 74 6776–6779.