An IMDbPro membership is taxable in the following U.S. states:
Sales tax is calculated based on the combined state and local tax. Tax is determined based on your billing address listed in the Payment Methods section. To ensure you are charged correctly, please make sure your billing address in the Payment Methods section is up to date.
You can view a breakdown of your charges including the amount of tax you were charged by viewing your Receipts.
If you are refunded a membership fee that included sales tax, the full amount including tax will be refunded to your payment method.
If you reside outside of the US, please see more information on Sales Tax charges here VAT charges.