The California Secretary of State information advises that you must register before doing business in California, which is a pretty common rule in most states. Therefore, you should register as a foreign LLC before actually commencing to do business. If you have already started, register immediately. The initial cost is only $70 and you can register through the forms on line.
The applicable Code section (please see the first link below) states that your LLC must be registered ""[b]efore transacting intrastate business in this state".
As concerns what constitutes transacting intrastate business, please see the post at the second link, below.
This information does not constitute legal advice and does not establish an attorney-client relationship.
Attorneys Sprang and Schultz gave good responses, which I fully endorse. However, there is the question of the need to form a company in another state. Are you doing business in that state? Is there a need to be registered both there and here? If you are not doing business in that other state, you might save money over the long run by just starting a California LLC here, and skip the need to file things in two states.
www.bayoaklaw.com. 510-208-5500. This answer does not create an attorney-client relationship. It is not legal advice, because it is only of a general nature. Please contact a lawyer qualified in your jurisdiction to discuss your situation in confidence, using your factual details. Avvo answers are only general legal responses. Item 9 of Avvo.com's Terms and Conditions are incorporated in this disclaimer as though it were printed here.
"Doing business in California" can be defined in various ways. The California State Board of Equalization, for example, considers the following "doing business in California":
If you have an office, sales room, warehouse, or other place of business in this state (even if the location is only temporary), or; Have a sales representative, agent, or canvasser operating in this state, or; Receive rental payments from the lease of tangible personal property located in this state.
The Franchise Tax Board uses an even broader definition: "Doing business" means actively engaging in any transaction for the purpose of financial or pecuniary gain or profit. (R&TC Section 23101).
California's arm is very broad.
This answer does not constitute legal advice and is provided for informational purposes only.