@MarilynG1 's answer may not necessarily be the case. Due to a 2019 court decision (the Bindley decision), CA may now tax non-resident sole proprietors who provide services to CA-based clients, even if the sole proprietor never set foot in California.
https://www.coblentzlaw.com/california-office-of-tax-appeals-gives-precedential-authority-to-bindley...
https://www.calcpa.org/news/2019/12/19/tax-net-widens
https://www.halversontax.com/out-of-state-taxes-california/
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
