The reality TV star - who recently reconciled with her spouse, months after filing for divorce in July - is planning an intimate ceremony "at a secret location on a beach" because her previous two weddings did not feel real.
Heidi - who first eloped to Las Vegas with Spencer in November 2008 before marrying again on their reality TV show 'The Hills' in April 2009 - said: "Last time I had Lauren Conrad telling me to leave, The Producers telling Spencer to leave me at the altar and it was just really awful.
"I had my mum yelling at me telling I needed my step dad to walk me down the aisle not my real dad, it was just so awful and everyone was just so mean, and no one there wanted us to get married they just wanted a show, so now this is real.
"We had a lot of voodoo on the last one so I'm ready for a new marriage."
Although the pair have already had two wedding ceremonies, Heidi said today's nuptials feel like her first.
She explained to Kyle Sandilands and Sophie Monk on Sydney's 2Day FM radio station: "This is like our first marriage. I feel like our first one was an elopement and we had so many margaritas and it was such a crazy time. And then the second one wasn't our wedding. It was just a 'Hills' wedding and it was for all the people there and it was about everyone else."
"We deserve a second chance at our marriage and really having this moment and not being robbed of this."
Spencer also admitted he didn't enjoy his last wedding, branding it "fake".
He said: "It was a movie, it was a script and it didn't feel right. No one in that building wanted us to get married. It was a nightmare."