if:
- You pay at least 90% of the tax you owe for the current year, or 100% of the tax you owed for the previous tax year, or
- You owe less than $1,000 in tax after subtracting withholdings and credits
每年报税前先付了，保证每年税表上都退回几十刀，这样每年You pay 100% of the tax you owed for the previous tax year。每年这样做应该就没有罚款了？觉得应该不这样简单。
正常如果是1 月1号卖房估计欠税2万，1 月15号前应该付了这2万tax underpayment，等待下一年4月15付这2万应该不行，有罚款。但上面做法就可以不交罚款？
