How long do I have to have had my UK Drivers License before I can drive in the US on holiday?

There is no time limit in the U.S. As long as your U.K. license is current, and valid you can drive in any of the 50 states. Also you do NOT need the, so called, international driver permit. Nor do we do that manual/automatic transmission thing you Brits do either. One problem you may have is that most U.S car rental/hire agencies require the primary driver to be 25 or older. Some may rent/hire to a 21 year old, but you would be charged an underage surcharge making the car very expensive. One thing in your favor is that the state of Florida, being a major tourist destination, has some of the lowest car rental/hire rates in the U.S. Cars are dirt cheap there.

You would have to check each rental company policy on both age of driver and number of years license held to answer your question. This is from the Hertz website. Age Differential Charge Policy On most retail rentals at corporate locations and participating licensee locations in the US, Canada, Puerto Rico and St Thomas (USVI), the minimum age is 25 without an additional Age Differential Charge, and 20 with an additional Age Differential Charge. The Age Differential Charge is either $15/day or $25/day, depending on the vehicle rented. Minimum age for Prestige & Adrenaline Collections, as well as select high performance vehicles, is 25. In Mississippi, the minimum rental age is 21. So they just say you need a valid license and will charge you more for being under 25. check out others Good luck !