The deadline for a subcontractor to file a California mechanics liens is typically 90 days after completion of the work of the improvement. However, if there is a Notice of Completion or Notice of Cessation has been filed on the project; the deadline to file will be reduced to a mere 30 days after one of these two notices is recorded. Missing this deadline to file is fatal to your mechanics lien rights.

Before filing a lien claim, there is one more thing you can try to induce payment. This is known as sending a Notice of Intent to Lien. Consider this letter a final warning, stating that if payment isn’t forthcoming in x amount of days you are willing and able to file a mechanics lien against the property. This should be sent to both the general contractor and the property owner to get your debt the full attention it needs. This is not a formal requirement, but is usually pretty effective at inducing payment,

Here’s an article that may prove helpful: How to File California Mechanics Lien | A Step-by-Step Guide to Get You Paid