sales tax collected when not wanted

I have sales tax set to NO. For my very first sale however, the user was charged sales tax. I don't see any other places where sales tax is referenced. How can I fix this? There are big penalties for charging sales tax when it's not legal to do so.

Thanks!

Hi

I guess the Sales tax is setup in your Paypal account and that's the reason Paypal charges it? Could you please check ?

Tuan