You need one per person entering Jamaica. I followed a suggestion on TA to print off a blank form at home and fill it out with all our info. You could highlight the applicable questions as well. Then just have in your bag (along with your blue/black pen!). That way, all you have to do is copy your info onto the official form on the plane. You don't have to fumble through your passport and itinerary/other papers on the plane...in cramped quarters....and you may be tired and not as sharp as usual. I thought it worked great!