be sure you have more than the minimum amount needed in your account - i park at mco and my sunpass let me in but when i tried to exit the next day i was denied. when i called sunpass they said i had gone below what it cost to park. turns out i did have enough in the account because they added to it when i hit my minimum, but it was below what i needed when they looked. they only look when you enter to see if you have the funds to exit. and they added funds from my credit card after that

now i keep it funded at a much higher minimum - although now i do not use the sunpass for parking. it took forever for me to get out because i did not have a ticket and by the time they verified my entry time i could have been half way home

but driving toll roads in florida without a sunpass is not a good idea - many exits do not have a toll collector - you need exact amounts.