You may have just tried to ship a special bottle from your favorite winery to a friend or relative, only to discover that for some reason they would not allow you to. Unfortunately for consumers, the US allows each state to control their own laws regarding wine, and there is no uniform interstate shipping regulations.
Each state has its own agreements regarding what other states are allowed to ship there.
Often, a winemaker will need to have a license to ship to another state, a cost they may not find worthwhile.
To add to the confusion, shipping companies have their own rules. Usually, a shipment of wine needs to be signed for, by an adult. And sometimes they even demand that the recipient be sober!