California rent increase law

For a month-to-month or shorter tenancy, give written notice of a rent increase at least 30 days before it takes effect, or at least 90 days if the increase, alone or combined with other increases in the 12 months before it takes effect, is more than 10 percent of the rent charged at any time in those 12 months. Deliver it personally or by mail; a mailed notice gets five more calendar days when mailed to an address in California.

Cal. Civ. Code § 827(b) Cal. Code Civ. Proc. § 1013(a)

• The 90-day rule does not apply to an increase caused by a required recertification of the tenant's income or family size; that notice is 30 days. Cal. Civ. Code § 827(b)(3)(B)
• Most housing that is more than 15 years old is also subject to a statewide cap on the size of increases. Cal. Civ. Code § 1947.12(a)(1), (d)(4) See Rent caps and local rules on the California page
• If a tenant who is not behind on rent makes a good faith repair notice or complaint, you may not raise rent within 180 days to retaliate for it; an increase for a lawful reason, stated in good faith in the notice, is allowed. Cal. Civ. Code § 1942.5(a), (f), (g) See Retaliation on the California page

For most housing, an owner may not raise rent over any 12 months by more than 5 percent plus the regional change in the cost of living, or 10 percent, whichever is lower, measured from the lowest rent charged in the prior 12 months, and in no more than two increases in that time. The rule applies until January 1, 2030.

Cal. Civ. Code § 1947.12(a)

• You may set the starting rent for a new tenancy freely when no tenant from the prior tenancy remains. Cal. Civ. Code § 1947.12(b)
• Discounts or concessions the tenant accepted do not count toward the lowest rent, and the lease must list the gross monthly rent and any owner-offered discounts, incentives, concessions or credits separately. Cal. Civ. Code § 1947.12(a)(1)
• Exempt are, among others, affordable housing under a recorded restriction, housing under a stricter local rent control, housing with a certificate of occupancy issued within the previous 15 years, and a separately sellable house or condominium not owned by a REIT, a corporation or an LLC with a corporate member, but only if the tenants were given the statutory exemption statement in writing, inside the rental agreement for any tenancy that began or renewed on or after July 1, 2020. Cal. Civ. Code § 1947.12(d) Cal. Civ. Code § 1947.12(d)(5)(B)
• Cities and counties may have their own rent control and just cause ordinances; the state just cause rule gives way to a local just cause ordinance adopted by September 1, 2019, or a later one that meets the section's test for being more protective. Cal. Civ. Code § 1946.2(i)(1) Cal. Civ. Code § 1947.12(d)(3) See Just cause to end a tenancy on the California page
• Use the applicable metropolitan-area CPI-U for all items published by the federal Bureau of Labor Statistics. The statute identifies metropolitan areas and their counties, and addresses successor or newly published regional indexes. If BLS does not publish an index for the property's metropolitan area, use the California all-items CPI-U published by the Department of Industrial Relations. Select the index for the property rather than borrowing another city's allowable increase. Cal. Civ. Code 1947.12(g)(1)
• The effective date determines the CPI comparison. For an increase before August 1, compare April of the previous year with April of the year before that. For an increase on or after August 1, compare April of the current year with April of the previous year. If April data are unavailable for the applicable area, use March for the same pair of years. Round the change to the nearest one-tenth of one percent, then apply the statutory cap and any stricter local rule. Cal. Civ. Code 1947.12(g)(3)

If a tenant who is not behind on rent has in good faith given a repair notice, reported a suspected bed bug infestation, complained to you about habitability, or complained to a government agency, you may not recover possession, force the tenant out, raise the rent or cut services within 180 days because of it.

Cal. Civ. Code § 1942.5(a)

• It is also unlawful to raise rent, cut services, force a tenant out, sue for possession, or threaten any of these, to retaliate for joining a tenants' organization or lawfully exercising any legal right. Cal. Civ. Code § 1942.5(d)
• A landlord who retaliates owes actual damages, and punitive damages of $100 to $2,000 for each retaliatory act involving fraud, oppression or malice. Cal. Civ. Code § 1942.5(h)