Municipality taxes
Your act 20 company will have a small tax on gross revenue made from within the municipality
US tax witholding
if your entity is owned only by BFRs of PR, it’s exempt from US tax withholding on invoices from US entities. You may need to give US payers a complete Form W-8BEN-E so that they know not to withhold on these payments. They should not have to give you a Form 1099 each year if all that is true.