Do I need an International Driving Permit to drive a hire car in Florida? In short, YES, you do!
However, after some extensive research it has come to light that if you have a UK driving license and you are planning on driving in Florida then you will need an International Driving Permit. This came into action on the 1st January 2013 and can be purchased from your local post office - currently priced at £5.50.
As it stands we are aware that this is just a law that has been implemented in the state of Florida, however there may be a possibility that it will be adopted in other states so be sure to check with your local post office if you plan on driving in the USA.
You will find more information on this at your local Post Office and The AA.