Tshwane hawker's application
You need to visit their premises To apply for a trading permit, visit the Local Economic Development offices at:
Cnr Thabo Sehume and Pretorius Streets
You attend a workshop. The documents are listed on the link below for the hawkers licence.
They also require the street address where the trailer will trade to inform metro that you are allowed to be there which is actually and very convenient thing.
The application process after the workshop seems to take 2 weeks only so you will definitely need the trailer for them to inspect for the certificate of acceptability.