In the U.S., forming/registering a business entity (like an LLC or Corporation) is typically handled by the Secretary of State (SOS), while registering for sales tax and paying tax returns is managed by the state’s Department of Revenue (DOR) or Taxation Authority.
Below is the directory for all 50 states plus the District of Columbia.
Business Registration & Sales Tax Portals by State
Shortcut for Multi-State Sales Tax Registration
If you sell across state lines and need to register for sales tax in multiple member states, you can use the Streamlined Sales Tax Registration System (SSTRS). It allows you to submit a single, free application to register for sales and use tax in 24 participating states (such as AR, GA, IN, IA, MI, MN, NC, OH, WA, WI, and others) simultaneously.