why did my employer withhold too much or too little tax 
federal tax withholding is based on the information that you provide on your w 4 form which you fill out and give to your employer when you start a job if you are significantly overpaying or underpaying on income tax you ll probably need to revise this form with more up to date information if an employer doesn t make adjustments to an employee s withholding you might need to file irs form 843 to request a refund of the over withholding who qualifies for exemption from withholding employees with no tax liability for the previous year and who expect no tax liability for the current year can use form w 4 to instruct their employer not to deduct any federal income tax from their wage this exemption is valid for a calendar year 22the bottom linewithholding tax is the amount of money that your employer holds back from your paycheck and sends to the government as payment toward your income taxes anyone who earns income is responsible for paying income tax you could get a tax refund after filing your taxes or you may owe more money part of your tax bill depends on your withholding tax if you find that you end up paying more money on tax filing day you can lower that amount by requesting that additional money be held from your paycheck on the other hand having a smaller amount deducted from every paycheck may make it easier to satisfy your tax bill at the end of the year 