<prompt> Human: If you were to inflate your exemptions on your W-4 so that you pay no income tax, but pay your full income tax due come tax time would this eliminate the interest free loan you give the IRS over the year?  <response>: You have to pay a penalty for underpayment if you owe too many taxes at the end of the year: You should adjust your exemptions until your tax return is approximately 0. 