A deal to take over the reins from Ellis Short was announced last month, but Donald and his consortium needed to pass a number of tests with the EFL.
Those requirements have now been met, and Donald has revealed that the Black Cats - who will play in League One next season - can now move forward without any arrears.
At a press conference, Donald said: "We've given Ellis £40m, so that's the deal, and in return Ellis has tidied up his debt and that's now gone from the football club.
"Ellis was very clear he didn't want the debt, but we didn't want the debt either so we refused that. The reality is Sunderland is debt-free which, for the fans, is good news."
Donald also added that he hopes to announce a replacement for Chris Coleman within a week.