See https://www.ftb.ca.gov/forms/2020/2020-568-booklet.html#20_568-2
D. Who Must File
An LLC may be classified for tax purposes as a partnership, a corporation, or a disregarded entity. The LLC should file the appropriate California return.
Form 568 must be filed by every LLC that is not taxable as a corporation if any of the following apply:
- The LLC is doing business in California.
- The LLC is organized in California.
- The LLC is organized in another state or foreign country, but registered with the California SOS.
- The LLC has income from California sources (Nonregistered foreign LLCs, see Exceptions to Filing Form 568, below).
An LLC is not required to file a tax return and is not subject to the annual tax and LLC fee if both the following are true:
- The LLC’s taxable year is 15 days or less.
- The LLC did not conduct business in the state during the 15 day period.
