<prompt> Human: Hello,I recently got married and updated my W-4 to reflect that. Today I got my first paycheck since the change, and federal withholding went from 160 to 463. Does anyone have any idea what I might have done wrong? Wife and I both make less than 30,000 each. Thanks in advance.  <response>: What were your W-4 settings before? Single and how many allowances on line 5?What are your new W-4 settings? Married? Married but withhold at higher Single rate? And how many allowances?Did the gross amount of your paycheck change?Did most recent paycheck include an unusual amount of overtime or bonus?Its getting near the end of the year so not easy to make a dramatic fix -- but the online tool could be used. Supply it with info about your income and wifes income for full year, and how much withholding has happened of fed income tax to date this year. It can give you suggestion of how to change W-4s for rest of 2017 to avoid overpaying. If you make those changes now, youd want to revisit in January 2018 and make new settings for 2018. Were mostly puzzled because just changing from Single to Married and keeping the same allowances figure should result in less withholding, not more, because of the larger deduction and tax bracket sizes when married, and the algorithms default assumption that theres just one earner. 