If you incorporated your organization in California or registered your out-of-state ("foreign") nonprofit corporation in California, the Secretary of State is the agency you contracted with.
Domestic (Calif.-based) nonprofit corporations must file a Statement of Information (Form SI-100) every two years. Online filing is strongly recommended.
When to File
If you incorporated on May 5, 2019, for example, you'll file your Statement of Information every odd year (2021, 2023, etc.) by May 31st. (Don't forget to first file no more than 90 days after you incorporate.)
To File Your Statement of
File your Statement of Information online by clicking here and completing all the fields. (Remember that your President cannot simultaneously serve as either Secretary or Treasurer. But someone other than the President can hold the offices of both Secretary and Treasurer.)
Receiving a Stamped/Filed Return Copy
When you complete the filing and payment process, you'll be able to enter an email where a "stamped/filed" copy of the form will be sent after it's accepted.
By using their Business Search feature, once you locate your corporation you can download past filings for free.
Check your status
I recommend checking the Secretary of State's Web site every 6 months. It's the quickest way to find out if you're still in good standing with them. Click here to check your status.
(The Secretary of State's Website is particularly valuable as a "diagnostic" tool because delinquencies with other agencies will eventually show up there.)
A Common Cause of Suspension
Failure to file the Statement of Information is, in my experience, the single most common cause of corporate suspension.
To Resolve Suspension
The Secretary of State's number is 916-657-5448, but they're not always easy to reach. I usually contact the Franchise Tax Board to resolve compliance issues with the Secretary of State.
Out of State Corporations
If you're an out-of-state ("foreign") corporation registered in California, you'll need to file your Statement of Information annually. File it here.