Hi all, I just returned from a year working for the Mouse in the UK pavilion. The official rule for Florida is passports are needed for international visitors; the vast majority of places will ID anyone who appears to be under 30 although liquor stores tend to be 40! This isn't just enforced at Disney. I have friends that tried to use drivers licenses/provisional, sometimes with a photocopy of their passport, that were declined at various restaurants/bars in Orlando and Tampa. Officially, this rule also applies to Universal Orlando bars and restaurants (no photocopies!).
Disney, however, WILL accept an international drivers license with a photocopy of your passport. It doesn't even have to be a paper copy - we also accepted digital versions on a phone - as long as you have your actual drivers license or provisional with you. Do not try to bring photocopies of both - this does not work!
I used to carry my passport around with me every time I would go to a restaurant or bar in Florida, pretty much nearly every day for a year. So did most of my colleagues and friends that worked in the UK pavilion. I only had 2 friends that lost their passports in the entire year, and that was through the effects of alcohol and not someone stealing it!
Is it true that you can get served just using your UK license at Disney World? Yes. Are those people risking their jobs every time they do it? Yes.
I worked in the pub in the UK and I never served anyone who gave me an international license, including UK. It doesn't matter that I know that it is real and that it 'makes sense'. It does matter that Disney regularly send in mystery shoppers and observers to make sure that its Cast Members are being compliant to Florida State Law. Working in the pub, we got reminded about this CONSTANTLY and all Disney CMs working with alcohol are required to refresh their knowledge of these laws every so many weeks. I know of some pavilions in Epcot, or even particular CMs (there are a few that I knew in the UK pav) that are more easygoing and probably would serve those with just an international drivers license. If you get caught, you lose your job and have 24-48 hours to leave the country. Some pavilions really struggle with recruitment and will probably try and defend their CM to stop this from happening (Italy, Norway... there are a few others). The UK is NOT one of those pavilions - we are easily replaceable.
When I was working in the pub, I would have this problem with UK visitors everyday and it was probably the least enjoyable part of my job. You wouldn't believe some of the abuse we got!! This is honestly the reason why some less confident CMs working in Epcot accept these forms of ID - they are sick of having these arguments. This ultimately could be improved by Disney putting up the proper signage - something that is requested all the time by CMs in Epcot during meetings!
Sorry for the essay but overall: If you are under 30, or look under 30-35, yes, you can use your drivers license as long as you have a photocopy of your passport or just take a clear photo of it and save it on your phone. If you are going to Universal or elsewhere in FL, be prepared that they may want a passport or you will be refused to be served (anyone not following this rule is risking their own job - being served solely with an international drivers license is not the norm throughout the state!).