I avoid that entire hassle altogether, because I work with an employer of record. I still have all the advantages of running my own business, but also get to take advantage of other benefits that I might get working for an employer, like group health, etc. It's great because I get one W-2 regardless of how many clients I've worked for, and my taxes are already taken out before I get my money, just like working for a company. My understanding is that if you are going to owe more than $1000, you must file quarterly. For me, I find that to be too much administrative hassle, so the employer of record option works great in my case.