The T-type was essentially an AEC K-type stretched in length by 2 ft 3 in (0.69 m), with the front axle moved rearward. This gave the vehicle a somewhat awkward appearance. The length was outside the then-permitted dimensions for buses in London. Only one vehicle was built, and was it used in trial service in London during early 1920. Following the trials, the permitted length was increased, and the AEC S-type was developed.