<prompt> Human: I have browsed PF posts and found a lot of information about 1099 income and estimated taxes. I am trying to educate myself about the rules regarding income I will earn in 2017. I am making this post to learn a bit more and to ask the question: if the federal, state, and county governments get the appropriate money from me, do they care what income source it comes from? Does it raise red flags if I dont pay them they way they expect me to?A few details in case they help anyone willing to provide some advice. Married, no kids owed 400 after filing 2016 taxes wife earns 40kyr W2 income I earn 50kyr W2 incomeStarting this month I will earn 750-1250mo additional 1099 income by doing part time consulting.If my federal withholdings are 20 of my monthly paycheck, can I take 20 of what I earn from my part-time consulting work and withhold it from my W2 paycheck as additional withholding towards federal taxes, skip paying quarterly taxes, file at the end of the year, break about even, and not think about any of this until January? Can I adjust my W4 as much as I want in case the consulting hours I bill trend up or down on a quarterly basis?Thanks!!!  <response>: Its entirely fine to over-pay taxes from your W2 job to help pre-pay the taxes for your 1099 job. I did it the past 2 years, and yes - skipped the quarterly payments. 