My GC is trying to overcharge me in the final invoices of a remodel project in northern CA (San Mateo County). I've tried to show him my disputes on 2 line items (electrical sub work and sport court sub work) where he's overcharging me. I'm willing to pay and close out this project, but not at his over-charged total. He never did submit a preliminary notice. He's threatened to put a lien on my house. I'm trying to understand my options and remedies. I'm wondering if I should pay him an amount and push for mandatory arbitration on the remaining disputed amount with the CA state contractor's licensing board.
Yes, a general contractor can file a mechanics lien even if the amount they're billing is in dispute. In fact, that's a pretty common cause for mechanics lien filings. Further discussion here: Do I Still Have Lien Rights If There Is a Dispute as to What I Am Owed?
Granted, keep in mind that doesn't mean their lien claim is proper. A CA lien claimant can only file a mechanics lien for the lesser of the contract price or the reasonable value of the work performed under § 8430 of the CA Civil Code. So, if the claimant files a lien claim for more than what they are due, then it may be possible to have the lien claim tossed aside or at least reduced.
Regarding preliminary notices - keep in mind that California GC's don't need to send preliminary notices unless there's a lender for the project. So, if there's no construction lender, then preliminary notices probably shouldn't come into the equation when assessing a general contractor's lien rights.
Finally, I think this article will be useful: A Mechanics Lien Was Filed on My Property – What Do I Do Now?