Affiliate nexus is where an out of state business (remote seller) has a relationship agreement with an in-state affiliate agent. The remote seller would be required to collect sales tax from customers in the state where the affiliate is located. This is the equivalent to traditional physical presence nexus laws where a company has an independent sales agent go into a state to procure sales. It is basically saying that the affiliate is part of the remote seller’s sales team. Currently all states that levy sales tax have affiliate nexus laws with the following exceptions:  The District of Columbia, Indiana, Maryland, Massachusetts, Mississippi, North Carolina, North Dakota, New Mexico, Tennessee, and Washington State.