Al has used the correct word ... it's a Use Tax and is due the state
Here in CT this is the way the law reads
From the CT State Revenue Dept.
"The Customer’s Responsibility"
"In cases where the online retailer does not have to collect sales tax, it is the customer’s responsibility to pay the tax—in which case it is known not as a sales tax but, rather, a “use tax.” According to guidance from the DRS, “Common purchases that are subject to use tax would be supplies or equipment purchased by Internet or mail order sales since the vendor is rarely required to collect sales tax.”
My general understanding is
If a out of state seller or vendor has no physical presence in the state that the sale is being made to ... the seller/vendor is not require to collect the tax
But if the seller or vender has any physical presence in that state that the sale is being made to in the form of a outlet .. store ..warehouse or even a office ... then the seller is required to collect the tax
Again that is from the CT State Revenue Department
Al thanks again for the clarity ...