Instant Criminal Background Check System (NICS) to prevent firearms sales to such prohibited people. Federal Firearms License (FFL) system The Gun Control Act mandated the licensing of individuals and companies engaged in the business of selling firearms. This provision effectively prohibited the direct mail order of firearms (except antique firearms) by consumers and mandated that anyone who wants to buy a gun in an interstate transaction from a source other than a private individual must do so through a federally licensed firearms dealer. The Act also banned unlicensed individuals from acquiring handguns outside their state of residence. The interstate purchase of long guns (rifles and shotguns) was not impeded by the Act so long as the seller is federally licensed and such a sale is allowed by both the state of purchase and the state of residence. Private sales between residents of two different states are also prohibited without going through a licensed dealer, except for the case of a buyer holding a Curio & Relic license purchasing a firearm that qualifies as a curio or relic. Private sales between unlicensed individuals who are residents of the same state are allowed under federal law so long as such transfers do not violate the other existing federal and state laws. While current law mandates that a background check be performed if the seller has a federal firearms license, private parties living in the same state are not required to perform such checks under federal law. A person who does not have a Federal Firearms License may not be in the business of buying or selling firearms. Individuals buying and selling firearms without a federal license must be doing so from their own personal collection. Under the Gun Control Act, a federally licensed importer, manufacturer, dealer or collector shall not sell or deliver any rifle or shotgun or ammunition for rifle or shotgun to any individual less than 18 years of age, nor any handgun or ammunition for a handgun to any individual less than 21 years of age. Gunsmith and factory repair exception While the Gun Control Act prohibits the direct mail-ordering of firearms, a person may ship a gun via contract carrier (such as United Parcel Service (UPS), United States Postal Service or FedEx) to a gunsmith (who has an FFL) or the gunmaker's factory for repairs or modification. After the repair work is done, the gunsmith or the factory