A universal background check for guns is a policy that requires a background check for all gun sales or transfers, regardless of where they occur or who is involved. This includes sales at gun shows, private sales between individuals, and sales made online. The idea is to close loopholes in existing laws that currently allow some gun purchases to occur without background checks.
Proposals in the United States, as part of gun control to curb gun violence, would require all gun sales or transfers to be recorded and go through the National Instant Criminal Background Check System (NICS), closing what is sometimes called the private sale exemption. Universal background checks are not required by U.S. federal gun law, but at least 21 states and the District of Columbia currently require background checks for certain private sales of firearms.