An individual owes consumer use tax on an out-of-state purchase when the item purchased is subject to North Carolina sales tax, and the retailer making the sale does not collect sales tax on the sale or the state sales tax rate imposed by the other state is less than the state sales tax rate imposed by North Carolina.

Out-of-state retailers that are not "engaged in business" in North Carolina are not required to collect North Carolina's tax. However, some out-of-state retailers voluntarily collect North Carolina tax as a convenience to their customers. Out-of-state retailers include mail-order companies, television shopping networks, firms selling over the internet, and other retailers.

Essentially if you bought something online and paid sales tax for it, then you don't have to pay use tax. But if you bought something online and paid no sales tax, then you used it while in North Carolina, you need to pay use tax on the item at the sales tax rate.