Florida's Department of Motor Vehicles determines what kind of vehicles need to be registered, which ones need to be titled and which ones need both. Fortunately, the process of registering and titling vehicles --- even a previously untitled trailer --- is a simple one, handled through your local county tax collector's office.
Find out how much your trailer weighs. If it's less than 2,000 pounds, it doesn't require a title for registration in Florida. If it's more than 2,000 pounds, you'll need to apply for a new title at the time you register it.
Take proof of ownership for the trailer and proof of insurance to your county tax collector's office, which issues Florida tags and titles.
Complete and sign Florida's title application form (available online) and pay the title fee to the tax collector if your trailer weighs 2,000 pounds or more. As of March 2011, title fees were $77.25 for new vehicles, $75.25 for used Florida vehicles and $85.25 for vehicles from outside the state.
Purchase or transfer your trailer's Florida tag by paying the appropriate tag fees and registration costs.