what are irs safe harbor rules 
irs safe harbor rules allow you to avoid a penalty or pay a reduced penalty if you meet certain conditions an underpayment penalty with the irs can be avoided if you owe less than 1 000 or pay more than 90 of your tax obligation for the year 1can you make estimated tax payments all at once some taxpayers such as sole proprietors partners and s corporation shareholders must pay taxes at least quarterly if they will owe more than 1 000 these payments are referred to as estimated tax payments you cannot pay estimated tax payments all at once unless you do so at the beginning of the year you can pay monthly in advance if that suits your budget better 10the bottom lineyou could end up paying an underpayment penalty if you don t pay enough in estimated taxes tax withholding or taxes due check to see if you qualify for an exemption or reduced penalty if you re charged a penalty the best way to avoid underpayment penalties is to be sure that you pay your taxes on time meaning around the time you earn it not the following april if all or nearly all of your income is from an employer you shouldn t have an underpayment problem if you do check the details on your w 4 form for errors that caused your employer to withhold less than necessary from your paycheck 