I'm 14 and will be 15 in March which is when I'll probably be getting the kart. I thought the same that you can race Seniors at 15 but I checked on Motorsport Ireland's site and it said 16+. I've checked out IrishKarting.com too. Great site. I've found 2-3 Seniors in my budget but I'm not sure what the ages are with 2 sites saying different