<prompt> Human: Wife and I were married in October and are filing jointly for the first time. My income 47k, hers 90k. Both of us received tax refunds last year, but I just finished going through TaxAct and it says we owe more than 10,000? I am by no means tax-savvy, but I would think that our tax situation shouldnt be dramatically different now that we are filing together? We are still in similar tax brackets to when we were filing separately as single people. Does anyone have any idea of potential errors on my part? As a side note, I changed jobs last April and have 2 W-2s . As far as I know, I didnt sign for any unusual exemptions so my withholding should be the same as it was before.Any help is appreciated!  <response>: Did you by any chance change your W-4 settings at work to the married check box during 2016 at some point? That could have caused underwithholding if you did not also complete the two earners worksheet on W-4 page 2. When both spouses work, special adjustments to the allowances figure on both your W-4s may be necessary if you use Married check box.If you both kept W-4 set to Single then you will need to provide more info about what amounts were withheld at all your jobs and what your incomes were. Being 10K shy if your tax is 20K is significant, so it certainly is worth figuring out, if only to avoid that kind of shock next year. 