All four banks have ATMs at most of their branches. For example, Belize Bank has ATMs at nine of its eleven branches.
You can use your ATM/check card to get cash (in Belize $) from the Belize Bank on Front Street. It works 24/7. You do have to put your card in a slot to open the door to the machine. Also, hotels and at least bigger restaurants and shops accept, but there is a service charge that varies. Remember, that's Belize $, so if you put in $200, you get $200 Belize.
There is a daily limit on withdrawals, $500 BZe per day,