Legal Question in Tax Law in Massachusetts

I assume you are referring to a commission sales job. The rules are the same as for any employee, the company must withhold taxes on commissions paid and pay unemployment for you. If you are asking about mileage or charges for personal use of a company car, those can be obtained from the IRS.

If you are not reimbursed mileage or do not get a company car, then the expense is a non-reimbursed business expense. I suggest you keep track of your mileage in writing in case of audit.

I hope this answers your questions. If not you can contact me.