California law states that completion means when the work is actually completed. This statement does not give a very clear definition of completion. The law further states that occupation or use by the owner or its agent accompanied by a cessation of labor is equivalent to completion. Also, cessation of labor for a continuous sixty (60) days would be the equivalent of completion. Acceptance of the owner or his agent no longer constitutes completion on private works of improvement. With respect to public works, the acceptance by the public entity is deemed completion.
Determination of the date of “completion” is a factual analysis and will be decided on a case-by-case basis. Typically, actual completion consists of full performance of the contract. However, subsequent minor changes, or correction of defective work or repairs may be considered warranty work and not part of the original scope.
As can be seen, it is not easy to define completion. It is also hard to distinguish between warranty work and completion work under the original contract. If any work is done of any substance that is not warranty work, chances are that it will be deemed work to complete the original agreement. At any rate, if you are unsure of when actual completion is, do not wait file your lien just to be safe.