Trump, who is expected to accept the GOP's nomination here Thursday, funded his primary election run mostly through personal loans. His campaign started raising more money from donors in June.
It reported nearly $27 million in total receipts for the month and ended it with more than $20 million on hand.
The Trump campaign directed CNBC to Trump's past statements on his loan forgiveness. In June, Trump called the loans a "contribution to make America great again."
During the primary process, Trump touted his ability to funnel money into his campaign as evidence that he is not beholden to donors. But he has turned to more traditional fundraising ahead of the more demanding general election.