On Curacao the Antillean Guilder (ANG or NAF) is the official currency. Although at many places the US dollar is also excepted. The official exchange rate between US dollar and Antillean Guilder is 1,78. These currencies are monetarily connected, which should result in similar exchanges always. Be aware companies may vary this exchange rate when excepting cash dollars.
On Curacao at ATM’s you will most likely be able to withdraw either Guilders or US dollars.
Like every country, Curacao has its own customs when it comes to tipping. For example, when you are going to a restaurant on Curacao, you will find that some places add a service charge to the bill. This surcharge can be seen as a tip and is shared among the waiter and the rest of the kitchen staff.
Nevertheless, when you are satisfied with the service, tipping is a good way to show your appreciation.
When shopping at most big supermarkets and the minimarkets, you will find people at the cash register who want to help you pack your groceries and bring them to your car. It is not mandatory to make use of this service but it is common practice on the island to let them help you and, again, it does show your appreciation.
What you give is discretionary but it is advised to give a couple of guilders to the person helping you.
Finally, when you are staying at a hotel and the bellboy brings your luggage to the room, the rule of thumb is to give a couple of guilders. The hotel will usually also add a service charge to your bill, which will be around 10-15% of the total amount. N.B. This does not include the additional government tax of 9%.