Do you have any documentation classifying you as a service technician?
If so, go directly to the manufacturers and seek an application for ISP (Independent Service Provider). If you are talking about working for the after-market service contract companies, they will hire most anybody, and do so with relative impunity. Either way, they all have set limitations on what they pay per call. Most of them require that you provide a substantial amount of contractor liability insurance. In my case a minimum of $1,000,000 liability policy got me in the door to several of them.
Sears Service Live, for example has an application HERE
Good luck with your new business! It is a satisfying and profitable career choice.