Heidi and Spencer -- WE'RE NOT BROKE!!!

Spencer Pratt is telling friends he DOES NOT owe hundreds of thousands of dollars to his former agent, despite reports to the contrary ... because he's NEVER had an agent!!!

TMZ spoke with sources close to Pratt ... who tell us the couple worked with a lawyer when they were negotiating their deals for "The Hills" back in the day ... but they never involved an agency. We're told Spencer insists the lawyer was paid IN FULL.

We're told Spencer is now studying political science at USC ... and at the moment, he isn't actively pursuing work in Hollywood.