<prompt> Human: According to federal law I have to repay. Fair enough as it was an employee error that generated the payment. Since it came with my regular pay, taxes and retirement contribution were taken out. Net received was about 6500. Did not spend it. Wrote a check to return it. According to federal laws my pay is being garnished to cover the balance which I never received but was paid as taxes. Adding insult to injury I have to file taxes and will pay AMT on the overpayment. This extra tax means I have to write a check to the IRS for far more than I planned. I usually try to cut it close and avoid AMT or overpayments. So now my cash flow is having to cover 8500 between garnishment and taxes...all to cover payments for money I never actually received. Am told DFAS will give me a tax certificate at the end of the year. My question is, what exactly is a tax certificate? Is it a credit that reduces my refund and then I pay taxes the next year? Is it a document I use to refile? DFAS will not answer my question in time for filing this year as my help ticket response time is estimated as 120 days minimum.  <response>: Make sure you notify your commander. Create an email trail with finance telling them that you were overpayed and are trying to resolve this as soon as possible. Since this is causing a financial hardship look into DD form 2789 waiverremission of indebtedness. When I was overpayed, it was not by this much so cant give you more advice. My advice would be to have your taxes filed by a pro and include a letter explaining the situation and why you wont be paying taxes on money you did not receive. I think you should get your first sergeant involved to get an answer on what a tax certificate is and how this will get sorted out. 