Donald Trump refused to show his tax returns too the public, with is breaking a tradition of all future presidents.
In one of the last debates Hillary said that in the late 1970s that casino regulators showed that he didn't pay any taxes. So if he didn't pay his taxes back in the 70s who is to say he hasn't paid taxes period. http://muckrakerfarm.com/2016/10/donald-trump-tax-records-show-avoided-taxes-nearly-two-decades-times-found/#more-2494