What is a "volunteer seller?"
The term “volunteer seller” is defined in the CSP contract Section D.2.

This definition is only used to determine when a CSP will receive compensation from a Streamlined state for providing services to the seller.  

This definition does not determine a seller’s legal requirement to register to collect and remit sales and use tax in a state.  Compensation under the CSP contract is to compensate the CSP for providing their services and is not payment to a seller for the administration of any state or local sales tax.

For a CSP to receive compensation for services provided to a “volunteer seller,” the seller must register through the Streamlined Sales Tax Registration system (SSTRS).