Over the years, Donald J. Trump or his businesses have been accused of stiffing carpenters, dishwashers and lawyers, leaving a trail of lawsuits and grudges in his wake. Now he is in a billing dispute with one of his own campaign aides.

Mr. Trump’s most recent filing with the Federal Election Commission indicates that his campaign has disputed a bill for $766,756 from a vendor, the well-regarded Republican pollster Tony Fabrizio.

The amount is listed as a “contested debt” in the Oct. 27 filing. Under F.E.C. rules, contested debt refers to “a bona fide disagreement between the creditor and the committee as to the existence of a debt or the amount owed by the committee.”

Mr. Fabrizio, who records show was paid another $623,629 in September by the Trump campaign, did not reply to an email seeking comment. A campaign spokesman, Jason Miller, said the debt was “an administrative issue that we’re resolving internally.” He declined to elaborate. The dispute was reported by The Washington Post.