The C15TA armoured truck was developed by General Motors Canada along a concept lines of the American M3 scout car.

In 1943 the Canadian Army policy was to use the 'CAPLAD' 3-ton armoured lorry then in development for their personnel and ammunition carrying needs for the invasion of France.

The CAPLAD was cancelled as not meeting requirements and it was decided to use the 15-cwt and American-built M14 half track trucks for personnel and ammunition carrying respectively.

With further delays, the Canadian Army adopted the same proportions of White Scouts and M14s as the British and were supplied with sufficient of these via the UK to meet their needs.

The C15TA was used by the British and Canadian units in the Northwest Europe campaign as armoured personnel carrier and ambulance (CT15AA), After the end of the hostilities, many vehicles were left in Europe and were subsequently employed by armies of the liberated European countries, including Belgium, Greece, Denmark (as M6 Mosegris), the Netherlands (which received at least 396 units), and Norway.