Rental Property, I rent a home from an owner through rental agreement (Real Esate Company), the owner has now moved onto a new Real Estate company

Sounds like either a communication problem between the Landlord and his previous rental agency or a bad break up between the Landlord and the previous rental agency.  Either way, sounds like you’re the one stuck in the middle.  The first thing I’d want to see is the lease; presumably, the agency used the FL Realtors – Residential Lease for Single Family Home or Duplex.  Under parties, it should only have you and the Landlord.  The rental agency works as the Landlord’s agent.  Generally, it will have provisions that basically you deal with them for everything unless the landlord says differently…sounds like here the Landlord is saying differently.  Have you been asked to sign anything with the new rental company or have you been given any written notice to pay the new rental company?  I would want to have something in writing from my landlord before I start paying the new folks.  You might find it helpful to spend a little time and a few bucks to have an attorney review your lease and perhaps clear up the communication issue for you.  As to whether the old can take you to court, they may try assuming that they are still legally the Landlord’s agent; however, if the Landlord ends such relationship, then the Landlord would be the one to evict.  Main concern here – figure out to whom you are legally obligated to submit the check – and that requires the lease agreement and any written notices you’ve received altering the agency relationship.