Six years as an independent contractor. I was making good money and could have kept going. But everyone's hand is now in my pocket. I am dealing with IRS audits. State governments are requiring annual "right to work fees" in addition to paying state income taxes when I am physically in the state. I am required to get a suite of liability insurances by the prime. I am advised to get expensive disability insurance. I am paying 2% in corporate state taxes. I kept my own books but had an accountant do everything else.
I did a really good job keeping overhead to near zero. I made the customer provide all software and hardware. I didn't do any marketing, because my services were in demand and word of mouth kept me 100% billable.
When I look back, I am not sure the hassle was worth it. I look at some of the others of large companies I was subbing for and their life is unappealing to me. I often worked side by side with these guys, and they would take a call every five minutes dealing with a crisis. And running their businesses is infinitely more complicated than mine. I worked about 60 hours a week. They must have been at 80+ which means their job is their life.