<prompt> Human: Double income, no kids. Combined income over 100k. My wife worked for company A from Jan-Aug of 2017. She now works for company B. We break even every year on our taxes within 50-100 owed or refundedUpon entering our taxes into TurboTax this year we are told we owe 5000. Typically we break even and aside from my wifes job change, nothing is different from last year. My wife pulled a few pay stubs and discovered that Company A was not taking out the proper amount of taxes. We verified that her W-4 was correct we both claim 0. Company A, for some reason, just didnt take out enough taxes on each pay check. We did the math and discovered that we do owe 2500 in taxes that were not deducted over the year. Cool, no problem. However, we now also have to pay an underpayment penalty of 2500. WTF! Im trying to make things right and am getting screwed. Is there anything I can do to avoid paying this ridiculous fee? Anything I can get Company A to do? Can I sue company A for this penalty fee since I submitted and have the correct W-4s I provided to them?Edit: my mistake. We both claim 1 on our w4sAssistant: What makes you think it was wrong? When you submit a W4 as married, it treats you as a one-income family, which can make your withholding wrong. Her job doesnt know about your income.Human: Because, other than my wife changing jobs, nothing has changed. We file the same way every year and this is the only time weve had a problem.  <response>: Yeah theyre saying you probably checked Married, not Married but withhold at higher Single rate on the W4. Not anything to do with how youre filing your taxes.That would have changed with the new job because the last job was probably withholding at the Single rate but unless they ignored that check box then it sounds like you just filled it out incorrectly, not that the job did anything wrong. 