ATS Groep has the following acknowledgements for contractors:

Class 8:
P1 - Electrical installations in buildings, installations in power generations, equipment for fire and steal reporting, telecommunication in buildings and their environment, equipment for mixed telephony

P2 - Electrical and electromechanical installation of industrial equipment and electrical outdoor installations

Class 6:
P3 - Installations of overhead power lines

S1 - Public telephone and telegraph equipment

Class 5:
S4 - Equipment for information processing and process control

Class 4:
T3 - Refrigeration installations