
Streamlined Sales Tax in 2026: One Free Portal, 24 States, and Free CSP Services for Multistate Sellers
A 2026 field guide to the Streamlined Sales Tax Project — the 24 member states, how the free SSTRS portal works, who qualifies as a CSP-compensated seller for free Avalara, TaxCloud, Sovos, or AccurateTax service, and when SST is the wrong choice for multistate online and SaaS sellers.










