On our last trip our departure tax was included in the plane fare, but we met a lady whose departure tax was not included. She went to the ATM and took out money for the tax. However the cash provided was Belize $'s and they would only accept US $'s for the tax. There was only one person in front of her in line at the bank window, but between the time the teller took a break and the time it took the one person in front of her to complete a simple transaction and the time it took for her to fill out the forms, she missed the plane. That was even though she had about a half hour when she learned she owed a departure tax. I still don't know why you have to fill out forms to change $BZ to $US or why the authorities only take US $'s but I will follow Gela's advice and "tuck away" the departure tax.