Jetter is correct, at least for residents of most states. In my state it is known as "use tax," which is numerically equal to the state sales tax. And there is a line-item on the state income tax return for it to be declared. If one enters zero on that line while having made out-of-state purchases during the year for which no sales tax was collected at the time of purchase, and for which sales tax would have been collected if the item had been purchased in-state, one is filing a fraudulent return.
Regards,
-- Al
Regards,
-- Al