I’m getting married in Aruba and would like to puchase many of the decorative items/favors etc. in the US. I would prefer to send items to the resorts wedding coordinator (via FedEx or DHL) a week ahead of the trip so that I know they’ve arrived (and have a couple of days to execute a back up plan if they dont) and not have to worry about carting around extra bags and connecting flights and lost luggage.
How do I find out if I will be charged taxes (or duty, I’m not exactly sure what to call it) on shipments ahead of time? And what are the charges? I also wonder, do the same fees apply when checking bags and going through airport customs? TIA

This could potentially be pretty complicated. If you send it unaccompanied (i.e., by mail), you may have to pay duties/taxes/processing fees on the freight when it arrives in Aruba (and that depends on the Aruban government import laws). The U.S. has a trade agreement that includes Aruba (Caribbean Basin Economic Recovery Act), so it might be duty free – either way you will want to talk to FedEx/DHL and ask them about it. Also see how long it will take to get through customs, because one week might be cutting it close.
I would also talk to the resorts’ wedding coordinator about it, since she has probably had people do this sort of thing before and they might have something set up with Aruban customs.
Usually the same fees do not apply when you have the baggage with you because you are allowed certain exemptions for gifts/items for person use. When coming back to the U.S., you get an $800 exemption (for Caribbean countries) for things you acquired abroad. Whereas, if you send them unaccompanied (i.e. by mail/UPS/etc), you have to pay duties (if it’s not duty free stuff), pay for customs clearance (if you use a private shipper like UPS) and/or processing fees, and also pay the shipping costs.
See link for more info on mailing stuff back to the U.S.: