Disclaimer (educational only): This article is general information, not legal advice. Rent caps and exemptions are highly fact-specific (property type, ownership structure, tenancy dates, local ordinances). Consult a qualified California landlord–tenant attorney before serving rent increase notices or relying on an exemption.
“How much can I raise rent?” is one of the most time-sensitive landlord questions in San Diego County because California’s rent cap uses a CPI-based formula and the allowable percentage can change each year depending on CPI publication schedules.
This guide is designed for mom & pop landlords and out-of-state investors who want a compliance-first understanding of:
- the statewide rent cap rule,
- the San Diego CPI input for the current cap window,
- the notice rules that apply regardless of the cap, and
- the City of San Diego local overlay you should not ignore if your property is inside city limits.
Key takeaways:
- Statewide rent caps (for covered units) limit increases to 5% + CPI, up to 10%, over any 12-month period.
- For a tenant who remains in place, rent generally can’t be increased in more than two increments in a 12-month period (for covered units).
- The CPI rule depends on timing: for increases effective on/after Aug. 1, use March/April comparisons as defined by statute (San Diego often uses March because of publication timing).
- Notice matters even when a unit is exempt: Civil Code § 827 requires 30 days’ notice for increases up to 10% and 90 days’ notice for increases over 10% (based on the prior 12 months).
- If your property is in the City of San Diego, local tenant-protection rules may apply to terminations (SDMC §§ 98.0701–98.0709).
California statewide law: the rent cap formula
California Civil Code § 1947.12 provides that, subject to subdivision (b), an owner shall not increase the gross rental rate more than 5% + the percentage change in the cost of living, or 10%, whichever is lower, of the lowest gross rental rate charged in the prior 12 months.
The statute also restricts increases to no more than two increments over a 12-month period when the same tenant remains in occupancy, subject to related restrictions.
“Percentage change in cost of living” — use the right CPI rule for San Diego
Civil Code § 1947.12 defines how to compute the “percentage change in the cost of living” using the applicable CPI-U and provides specific instructions that depend on whether the rent increase takes effect before Aug. 1 or on/after Aug. 1, and it includes a fallback to March data if April is not published for the geographic area.
For rent increases that take effect on or after August 1 of a calendar year:
- use the percentage change in the CPI amount published for April of that year and April of the immediately preceding year, OR
- if there is not an amount published in April for the applicable area, use the change published for March of that year and March of the immediately preceding year.
San Diego County’s current cap window (as of Feb 20, 2026)
BLS reported the San Diego-Carlsbad CPI-U was up 3.8% from a year ago (12 months ending March 2025).
Because the rent cap statute allows use of March when April is not published for the applicable area, this 3.8% CPI figure supports a 5.0% + 3.8% = 8.8% maximum cap (subject to the 10% ceiling) for covered units for the relevant annual cap window beginning August 1, 2025 through July 31, 2026.
Important: This is a statewide cap only for covered units and does not replace any local ordinance that is more protective. (For City of San Diego, see local callout below.)
Notice rules (these apply even if you think you’re exempt)
Separate from the rent-cap math, Civil Code § 827 sets notice timing for many residential rent increases:
- If the proposed rent increase (alone or combined with other increases in the prior 12 months) is 10% or less, notice must be delivered at least 30 days before the effective date.
- If the proposed rent increase is greater than 10%, notice must be delivered at least 90 days before the effective date.
Practical takeaway: Many landlord mistakes in California are not “math mistakes”—they’re timing/service mistakes. Civil Code § 827 is one of the first statutes a dispute will point to.
If you want compliant rent increases handled with correct timing, documentation, and tenant communication—without DIY stress—schedule a property management consult with Harland Property Management (Investors: 858-537-1681).
The City of San Diego vs. the rest of the County
San Diego County includes many cities and unincorporated areas, and local rules can differ.
City of San Diego (local ordinance): The City confirms its Residential Tenant Protections Ordinance is codified at San Diego Municipal Code §§ 98.0701–98.0709 and became effective June 24, 2023.
The City FAQ also confirms the ordinance generally applies to verbal and written residential leases with listed exceptions (see SDMC § 98.0703 referenced by the City), and it addresses topics like termination grounds and certain exemptions.
Outside City of San Diego: You still must follow California statewide rules (including Civil Code § 1947.12 and § 827) plus any other city-specific ordinances applicable where the property sits.
Want rent increases executed with compliance-first documentation and tenant communication? Get a custom management quote or schedule a property management consult with Harland Property Management (Investors: 858-537-1681)
Disclaimer (educational only): This article is not legal advice. Before raising rent, confirm whether your unit is covered, whether any exemption truly applies, and whether a local ordinance changes the analysis. Consult a qualified attorney for advice on your specific facts.
San Diego rent increase checklist (compliance-first):
Confirm whether the unit is subject to Civil Code § 1947.12’s cap (coverage/exemptions are fact-specific).
If covered, calculate max increase for the effective date window using the statute’s CPI rules (including the March fallback if April CPI isn’t published for the area).
Confirm you are not exceeding the “two increments in 12 months” rule for the same tenant (covered units).
Apply Civil Code § 827 notice timing: 30 days if ≤10%, 90 days if >10% (including combined increases in prior 12 months).
If the property is inside the City of San Diego, screen for RTPO applicability/exemptions (SDMC §§ 98.0701–98.0709 per City FAQ).
Keep documentation (calculation, notice, service method, effective date) in the property file.
FAQs
Q: What is the statewide rent cap formula in California?
A: For covered units, Civil Code § 1947.12 limits rent increases to 5% plus the percentage change in the cost of living, or 10%, whichever is lower, based on the lowest gross rental rate in the prior 12 months.
Q: Can I raise rent more than once in a year?
A: For covered units where the same tenant remains in occupancy over a 12-month period, the statute limits increases to no more than two increments in that 12-month period.
Q: What is the current San Diego County cap for the Aug 2025–Jul 2026 window?
A: Using the statute’s formula and BLS’s San Diego-Carlsbad CPI-U year-over-year change of 3.8% (12 months ending March 2025), the cap is 8.8% (5.0% + 3.8%), subject to the 10% ceiling, for covered units in that annual window.
Q: Do I always have to give 30 days’ notice for a rent increase?
A: Not always. Civil Code § 827 requires at least 30 days’ notice for increases up to 10% (considering increases in the prior 12 months), and at least 90 days’ notice for increases greater than 10%.
Q: Do notice rules apply even if my unit is exempt from the rent cap?
A: Civil Code § 827 governs notice timing for many residential rent increases; exemption from a cap does not automatically remove notice obligations.
Q: Is there “San Diego rent control” beyond the state cap?
A: The City of San Diego has a Residential Tenant Protections Ordinance codified at SDMC §§ 98.0701–98.0709 (per City FAQ), which is a local overlay separate from Civil Code § 1947.12.
Q: Where is the City of San Diego ordinance found, and when did it take effect?
A: The City FAQ states it is in SDMC §§ 98.0701–98.0709 and has an effective date of June 24, 2023.
