Yes, by law as a marketplace we have to charge sales tax for every state in the United States. We collect this from the buyer on all sales and submit this on behalf of the seller. We do not charge tax on behalf of international buyers or sellers. Please check with your local taxing authority for any rules and regulations you should abide by if you are outside of the United States.
Note that if you are a connected store, you may see sales tax on your systems. Be sure to filter and remove that when paying your state sales tax. We have already collected it.