Massachusetts' non-participation in the Streamlined Sales Tax (SST) program means remote sellers must adhere to state-specific sales and use tax collection and reporting requirements without the benefits of standardized SST guidelines. Remote sellers must manage compliance individually for Massachusetts, potentially increasing administrative burdens and complexity, especially for businesses operating in multiple jurisdictions. They cannot leverage SST software or simplified processes, necessitating dedicated systems and possibly professional tax assistance to ensure accurate tax collection and remittance according to Massachusetts’ distinct rules.