First and foremost, if wishing to file a California mechanics lien, the claimant must comply with the preliminary notice requirements.
In California, preliminary notice is required to be sent within 20 days of the date the claimant first furnished labor or materials to the project. This notice can be sent late, but the lien claim will only cover the labor and materials provided in the 20 days preceding when the notice is received.
The deadline to file a CA mechanics lien depends on the claimant's role on the project, and whether not a Notice of Completion (NOC) has been filed on the project. For any claimant, the default rule is 90 days from completion of the project.
If however, a Notice of Completion has been filed, the 90-day deadline can be shortened. For general (direct) contractors, if an NOC was filed, mechanics lien must be filed within 90 days from completion, or 60 days from when the NOC was recorded; whichever is earlier. For all other claimants, if an NOC was filed, the claim must be filed within 90 days of completion, or 30 days from when the NOC was recorded; again, whichever is earlier.
California has strict requirements, notices, and deadlines that must be met to properly file a mechanics lien. We have full breakdown of all the CA requirements here: How to File a California Mechanics Lien| A Step-by-Step Guide to Get You Paid.