I'm confused. I'm have a professional LLC which I started 2 years ago and am confused on the payroll taxes (ie. form 941). I haven't made any money but just have been breaking even in my business so I haven't drawn any salary other than reimbursing myself of expenses of the business. Since I dont' pay myself a salary, am I required to withhold social security and payroll tax? If so, what do I base it on, $0?