The IRS will not charge you an underpayment penalty

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

每年報稅前先付了，保證每年稅表上都退回幾十刀，這樣每年You pay  100% of the tax you owed for the previous tax year。每年這樣做應該就沒有罰款了？覺得應該不這樣簡單。

正常如果是1 月1號賣房估計欠稅2萬，1 月15號前應該付了這2萬tax underpayment，等待下一年4月15付這2萬應該不行，有罰款。但上麵做法就可以不交罰款？