Comment Re:It is the cost of "participation" (Score 1) 323
Legally, you do not have to pay any taxes until your file your tax return, but if you earn a taxable income of US$50,000.00, you will have to write a check for US$12,500.00 when you file your taxes.
Income taxes have to be paid throughout the year; if you are in a situation where you do not have an employer to do witholding on your income then you have to pay estimated tax payments. You can't just hold on to all the income tax money untill the end of the year and pay it in a lump sum; you'll be penalized for that.
http://www.irs.gov/businesses/small/article/0,,id=110413,00.html