Official & primary sources
Use these portals before making structural decisions; our educational articles only summarise them.
Federal — income & employment taxes
- IRS — Small Business & Self-Employed
- IRS Publication 17 (Your Federal Income Tax)
- IRS — Self-Employment Tax
Treasury & policy context
Business formation
State departments of revenue
State rules vary by nexus, apportionment, and entity — the simulator slider is illustrative. Examples:
California CDTFA, New York State Department of Taxation and Finance, Texas Comptroller.