Yes, there is no law in California which prohibits a tenant from pre-paying several months in rent, regardless of whether the tenancy is commercial or residential. Just make sure your lease or rental agreement clearly sets forth that the payments are for advance rent.
Frank W. Chen is licensed to practice law in the State of California. The information presented here is general in nature and is not intended, nor should be construed, as legal advice. This posting does not create any attorney-client relationship with the author. For specific advice about your particular situation, consult your own attorney.