I accept a job that pays me a signing bonus. I accept the job, and I receive my signing bonus, which is taxed appropriately. However, there is a clause in my agreement that states that if I leave my place of employment before a certain amount of time, I have to repay the signing bonus to the company.
I leave that position for another position that I perceive as better, and I am forced to return the money to my previous employer, for the full amount, without tax.
I no longer have the initial income, and I'm actually now out MORE money than I initially made, since I never go the amount that the taxes took in the first place. How is this resolved at the federal income tax level?