Cigarettes bought over the Internet, over the phone, or from mail-order catalogs generally don’t have Idaho tax stamps on the bottom of the packages and are considered unstamped. The penalty for having, buying, or using more than 10 packs of unstamped cigarettes is three times the cigarette tax due for each full or partial pack. The minimum penalty is $50.
When you buy cigarettes over the Internet, over the phone, or from mail-order catalogs, you’re generally not charged Idaho sales tax. In that case, you owe Idaho use tax. Use tax is a tax on the purchase of goods that you put to use or store in Idaho.
To pay the use tax, fill out 
Form 850-U.