Month-to-Month Rent Increase in California: Caps, Notice, and Coverage

In California, a landlord on a month-to-month rent increase can raise the rent no more than once or twice in a 12-month period, and the combined increase cannot exceed 5% plus the regional Consumer Price Index change or 10% of your prior rent, whichever is lower. That ceiling comes from the statewide Tenant Protection Act and runs through January 1, 2030. Even when an increase fits inside the cap, it is not enforceable until the landlord gives you proper written notice: 30 days for smaller increases, 90 days for larger ones.

How the Rent Cap Is Calculated

Civil Code Section 1947.12 sets the statewide ceiling. Over any 12-month period, your landlord cannot raise rent by more than 5% plus the percentage change in the regional CPI, or 10% of the prior rent, whichever figure is lower.¹ If your area’s CPI change is 3%, the cap that year is 8%. If CPI runs 6%, the formula would produce 11%, but the 10% hard ceiling applies instead.

The math starts from the lowest gross rent charged for your unit at any point during the 12 months before the increase takes effect. Temporary discounts, concessions, and credits the landlord offered are excluded from that baseline, so a one-time break on rent doesn’t permanently lower what the landlord can charge going forward.¹

A landlord can raise rent up to twice in a 12-month period, but the two increases added together still cannot exceed the annual cap.¹ Splitting one large hike into two smaller ones does not create extra room.

The CPI figure itself depends on when the increase takes effect and where you live. For increases before August 1, the percentage change comes from the April-to-April CPI figures published by the Bureau of Labor Statistics for your metropolitan area. For increases taking effect on or after August 1, the statute uses more recent data.¹ A tenant in a high-inflation metro faces a higher allowable increase than one in a region where prices have been flatter.

One important limit on the cap: when a tenancy ends and all prior tenants move out, the landlord can set the initial rent for the next tenant at any amount. The annual cap only governs increases after that new starting rent is established.¹ The protection follows your tenancy, not the unit.

How Much Notice the Landlord Must Give

Even an increase that fits within the cap does not take effect until the landlord delivers proper written notice under Civil Code Section 827. How much lead time depends on the size of the proposed increase compared with what you have been paying over the prior 12 months:

A written notice of at least 30 days is required when the proposed increase is 10% or less of the rent charged at any point during the prior 12 months, counted together with any other increases during that period.²
A written notice of at least 90 days is required when the proposed increase exceeds 10% of the rent charged at any point during the prior 12 months, whether on its own or combined with earlier increases that year.²

The 10% notice threshold is a separate rule from the Tenant Protection Act’s cap. It applies to all residential month-to-month tenancies, including those exempt from the statewide cap. A landlord with an exempt property who wants to raise rent 15% still owes you 90 days’ notice.

The landlord may deliver the notice by handing it to you personally or by mailing it under the procedures in Code of Civil Procedure Section 1013.² When the notice is mailed within California, five extra calendar days are added to the notice period.³ A mailed 30-day notice effectively runs 35 days; a mailed 90-day notice runs 95.

A rent increase delivered with insufficient notice or through an improper method is not enforceable. If the landlord tries to collect the higher amount before the notice period has fully run, you are not obligated to pay the difference, and a court would not uphold an eviction based on nonpayment of that unapproved portion.

Is Your Unit Even Covered?

The Tenant Protection Act does not cap rent on every rental in California. Several categories sit outside the cap, though the Section 827 notice periods still apply to every month-to-month tenancy regardless of exemption. The main exemptions:

Single-family homes and condominiums, but only when the owner is not a corporation, a real estate investment trust, or an LLC with at least one corporate member. The owner must also give you a specific written notice stating the property is exempt.¹
Housing that received its certificate of occupancy within the previous 15 years (mobilehomes excluded). This is a rolling window, so a building completed in 2011 became subject to the cap in 2026.¹
Owner-occupied duplexes, meaning a two-unit structure where the owner lives in one unit as a principal residence, provided neither unit is an accessory dwelling unit or junior accessory dwelling unit.¹

The single-family exemption has a catch that trips up many tenants: it only works if the landlord actually delivered the required written exemption notice. If you never received a notice stating your unit is exempt, the property is treated as if the cap applies, even when it would otherwise qualify.¹ The notice must include specific statutory language identifying which code sections don’t apply. Check your lease and any addenda before assuming you are uncovered.

The Tenant Protection Act also requires just cause before a landlord can terminate a month-to-month tenancy once you have lived in the unit for 12 months, which matters here because without that rule a landlord could evict you for refusing an unlawful increase and simply re-rent at the higher number.⁴ The same exemptions above apply to that protection as well.

Rent Increases After You Complain

California law separately prohibits a landlord from raising rent as payback for exercising your legal rights. Under Civil Code Section 1942.5, a landlord cannot increase rent, cut services, or try to force you out within 180 days of certain protected actions, including:

Complaining to the landlord about habitability problems
Filing a written complaint with a government agency about the condition of your unit
Participating in a tenants’ association or advocacy organization

The 180-day clock runs from your most recent protected action. If an increase arrives shortly after you reported a code violation, the timing alone creates a strong inference of retaliation. The landlord can still raise rent during that window, but only by showing the increase was planned for a legitimate, non-retaliatory reason. Threatening to report you or someone associated with you to immigration authorities is explicitly treated as retaliatory conduct under the same statute.⁵

What To Do If the Increase Is Illegal

If the amount exceeds the cap or the notice was defective, you have real remedies. Civil Code Section 1947.12(k) lets you bring a civil action against a landlord who demands, accepts, or retains any payment above the maximum allowable rent. The possible recovery includes:

Actual damages: every dollar you paid above the legal maximum.
Treble damages of up to three times the overpayment, if the landlord acted willfully or with fraud.
Attorney’s fees and costs, at the court’s discretion.
Injunctive relief ordering the landlord to stop collecting the illegal amount.

You have three years from the date of the violation to file suit.¹ The California Department of Justice recommends consulting a lawyer if you receive a notice that wasn’t in writing or wasn’t delivered on time.⁶ Save the notice, record the date you received it, and keep records of what rent you’ve paid. For smaller amounts, small claims court can be a practical path without hiring an attorney.

Local Rent Control Can Be Stricter

Dozens of California cities enforce their own rent control rules on top of the state cap. Los Angeles, San Francisco, San Jose, Berkeley, and Oakland all maintain local ordinances that frequently impose tighter limits than the Tenant Protection Act, and where a local law provides stronger protection, the local rule controls.¹

Local ordinances vary. Some restrict increases to once per year. Some peg the maximum to a fraction of CPI rather than 5% plus CPI. Some require landlords to register their rental units with a local housing agency annually, and a failure to register can block the landlord from collecting an increase at all.⁷ Local rent control typically applies to older buildings. Los Angeles, for example, covers properties built on or before October 1, 1978.⁸ If your unit was built after your city’s local cutoff, the state cap may be your only coverage. If it was built before, the local rule likely gives you more. The only way to be sure which rules govern your unit is to check with your city’s housing department or rent board.

The 2030 Sunset

The statewide rent cap and just cause eviction protections under AB 1482 are scheduled to expire on January 1, 2030, unless the legislature extends them.⁹ After that date, properties not covered by a local rent control ordinance would have no state cap on annual increases. Local ordinances run on their own timelines and would remain in effect independently.

1
California Legislative Information. California Code CIV 1947.12 – Residential Real Property Rent Increases
2
California Legislative Information. California Code CIV 827 – Change of Terms of Lease
3
California Legislative Information. California Code CCP 1013 – Service by Mail
4
California Legislative Information. California Code CIV 1946.2 – Termination of Tenancy
5
California Legislative Information. California Code CIV 1942.5 – Retaliation
6
California Department of Justice. Landlord-Tenant Issues
7
Los Angeles Housing Department. Rent Registry
8
Los Angeles Housing Department. Rent Control Property Overview
9
California Legislative Information. AB 1482 Tenant Protection Act of 2019