Starting side business with EAD

[classman]

I need to know how does one\'s EAD come into play when he/she wants to start a side business, while working for another employer ?. I know that one needs to fill an I-9 form based on EAD, if he/she starts a part time job with another employer. However, does the same apply for a side business of one\'s own also ?.

Please clarify.

Thanks