Interim championships initially appeared in scenarios where the current champion of any given division was forced to sit out for a long time, likely due to an injury. The first ever UFC Interim Champion was Randy Couture, who beat Chuck Liddell at UFC 43 in 2003 and that interim title bout was set because then-champion Tito Ortiz was out for an extended period of time. Historically, if the interim champion couldn’t attempt to unify the belts by fighting the UFC champion anytime soon, they’d go on to truly be a placeholder champion in the division, defending the belt. A great example of this is Renan Barão, who won the interim belt when Dominick Cruz was forced out of action. He defended it twice before being promoted to the undisputed champion.
This was the justification for most interim title fights until this modern era of the UFC. Nowadays, the UFC believes that title fights add value to PPV events and so there’s some extra incentive for adding extra belts into the mix when possible. It only takes a champion being out for a shorter amount of time, or fighting in another weight class, for an interim championship fight to be booked today. It’s looked at these days as more of a #1 contender belt than anything and even if you’ve been watching the UFC for the best part of a decade, you’ll struggle to remember a time when this hasn’t been the case.