Cal. Civ. Code § 827

(a) (1) Except as provided in subdivision (b), in all leases of lands or tenements, or of any interest therein, from week to week, month to month, or other period less than a month, the landlord may, upon giving notice in writing to the tenant, in the manner prescribed by Section 1162 of the Code of Civil Procedure, change the terms of the lease to take effect, as to tenancies for less than one month, upon the expiration of a period at least as long as the term of the hiring itself, and, as to tenancies from month to month, to take effect at the expiration of not less than 30 days, but if that change takes effect within a rental term, the rent accruing from the first day of the term to the date of that change shall be computed at the rental rate obtained immediately prior to that change; provided, however,
that it shall be competent for the parties to provide by an agreement in writing that a notice changing the terms thereof may be given at any time not less than seven days before the expiration of a term, to be effective upon the expiration of the term.
(2) The notice, when served upon the tenant, shall in and of itself operate and be effectual to create and establish, as a part of the lease, the terms, rents, and conditions specified in the notice, if the tenant shall continue to hold the premises after the notice takes effect.
(b) (1) In all leases of a residential dwelling, commercial real property by a qualified commercial tenant, or of any interest therein, from week to week, month to month, or other period less than a month, the landlord may increase the rent provided in the lease or rental agreement, upon giving written notice to the tenant, as
follows, by either of the following procedures:
(A) By delivering a copy to the tenant personally.
(B) By serving a copy by mail under the procedures prescribed in Section 1013 of the Code of Civil Procedure.
(2) If the proposed rent increase for that tenant is 10 percent or less of the rental amount charged to that tenant at any time during the 12 months before the effective date of the increase, either in and of itself or when combined with any other rent increases for the 12 months before the effective date of the increase, the notice shall be delivered at least 30 days before the effective date of the increase, and subject to Section 1013 of the Code of Civil Procedure if served by mail.
(3) (A) If the proposed rent increase
for that tenant is greater than 10 percent of the rental amount charged to that tenant at any time during the 12 months before the effective date of the increase, either in and of itself or when combined with any other rent increases for the 12 months before the effective date of the increase, the notice shall be delivered at least 90 days before the effective date of the increase, and subject to Section 1013 of the Code of Civil Procedure if served by mail.
(B) If the proposed rent increase for that tenant is caused by a change in a tenant’s income or family composition as determined by a recertification required by statute or regulation, the notice shall be delivered at least 30 days before the effective date of the increase as described in paragraph (2), and subparagraph (A) of this paragraph shall not apply.
(4) A landlord of a commercial real property shall include in the
notice information on the provisions of this subdivision.
(5) In all leases for commercial real property by a qualified commercial tenant, a rent increase shall not be effective until the notice period required by this subdivision has expired.
(6) Notwithstanding any other provision of law, a violation of this subdivision by a landlord of a commercial real property does not entitle a qualified commercial tenant to civil penalties.
(7) For the purposes of this subdivision, the following definitions apply:
(A) “Commercial real property” means all real property in this state, except dwelling units subject to Chapter 2 (commencing with Section 1940) of Title 5 of Part 4 of Division 3, mobilehomes as defined in Section 798.3, and recreational vehicles as
defined in Section 799.29.
(B) “Microenterprise” has the same meaning as that term is defined in subdivision (a) of Section 18000 of the Business and Professions Code.
(C) “Nonprofit organization” means any private, nonprofit organization that qualifies under Section 501(c)(3) of the United States Internal Revenue Code of 1986.
(D) “Qualified commercial tenant” means a tenant of commercial real property that meets both of the following requirements:
(i) The tenant is a microenterprise, a restaurant with fewer than 10 employees, or a nonprofit organization with fewer than 20 employees.
(ii) (I) Subject to subclause (II), the tenant has provided the landlord, within
the previous 12 months, a written notice that the tenant is a qualified commercial tenant and a self-attestation regarding the number of employees, at such time the protections under this subdivision come into place.
(II) Unless the tenancy is from week to week, month to month, or other period less than a month, the tenant provided the notice and self-attestation described in subclause (I) before or upon execution of the lease, and annually thereafter, at such time the protections under this subdivision come into place.
(c) If a state or federal statute, state or federal regulation, recorded regulatory agreement, or contract provides for a longer period of notice regarding a rent increase than that provided in subdivision (a) or (b), the personal service or mailing of the notice shall be in accordance with the longer period.