<prompt> Human: Hello rpersonalfinance, Im an international student here in the U.S.A and am currently in my senior year of college. I started working part-time with the university dining hall fall semester of my sophomore year Fall 2015. In each of my paychecks that i receive taxes are automatically deducted, and each year ive filled out my income tax forms in time for the tax return deadline. This morning i checked my mail and noticed that there was an official IRS billI checked claiming that i owed close to 1100 in unpaid taxes for the tax year ending in december 2015. I dont know what to do about this since im not at all familiar with the US tax system. But up until december 2015 i had only worked for one semester at 9.50hr before taxes for 12-13 hours per week. The sheer amount of this bill makes up close to 75 of my total income for that semester and i have documentation detailing my paycheck history. Is this an IRS mistake? are they common? or did i simply have my identity stolen somehow?Thanks.  <response>: Request a Wage transcript for 2015 from the IRS. It will show all the income that employers reported on your number. 