San Diego County’s maximum allowable rent increase drops to 8.2% for any increase taking effect between August 1, 2026 and July 31, 2027.
That is down from 8.8%. If you own residential rental property in San Diego County, this is the number that governs every rent increase you serve for the next twelve months — assuming the cap applies to your unit at all.
Here is the new figure, the math at common San Diego rent levels, who is exempt, and the one timing mistake that generates the most disputes every August.
The Short Answer
| Maximum allowable increase | 8.2% |
| Applies to effective dates | August 1, 2026 – July 31, 2027 |
| Formula | 5% base + 3.2% San Diego regional CPI |
| Prior year cap | 8.8% (5% + 3.8% CPI) |
| Statutory authority | Cal. Civil Code § 1947.12 (AB 1482) |
| Hard ceiling | 10%, regardless of CPI |
The cap applies per 12-month period, not per increase. You may raise rent twice within a 12-month window, but the combined increase cannot exceed 8.2%.
Why the Number Dropped
California’s Tenant Protection Act sets the maximum annual rent increase at 5% plus the year-over-year change in the regional Consumer Price Index, never exceeding 10%. The 5% base is fixed by statute. The CPI input resets every August 1.
For most California metros the statute uses the April-to-April CPI change. The Bureau of Labor Statistics does not publish an April figure for the San Diego–Carlsbad area, so the statute permits use of the March figure instead. That March-to-March number came in at 3.2% this year, down from 3.8%.
5% + 3.2% = 8.2%.
Nothing about your property changed. The inflation input did.
San Diego vs. Other California Regions
| Region | Cap, 8/1/2026 – 7/31/2027 |
|---|---|
| San Diego County | 8.2% |
| Los Angeles & Orange Counties | 8.7% |
| Riverside & San Bernardino | 8.1% |
| Core Bay Area counties | 8.8% |
| Remainder of California | 8.6% |
If you own units across county lines, do not apply one percentage portfolio-wide. Each property is governed by the CPI region in which it sits.
The Date That Matters Is the Effective Date — Not the Notice Date
This is the single most common compliance error each August, and it is entirely avoidable.
The applicable cap is determined by the date the increase takes effect, not the date the notice was served.
A 30-day notice served on July 20, 2026 for an increase effective September 1, 2026 falls into the new window. It must use 8.2% — even though the 8.8% cap was still in force when the notice went out. A notice drafted at 8.8% that takes effect in August is an over-cap demand from day one.
If you have notices in flight that were prepared before August 1, pull them and check the effective date.
Running the Math
Multiply current rent by 1.082 to find the maximum lawful new rent.
| Current Monthly Rent | Maximum Increase | Maximum New Rent |
|---|---|---|
| $1,800 | $147.60 | $1,947.60 |
| $2,200 | $180.40 | $2,380.40 |
| $2,500 | $205.00 | $2,705.00 |
| $3,000 | $246.00 | $3,246.00 |
| $3,500 | $287.00 | $3,787.00 |
| $4,200 | $344.40 | $4,544.40 |
Two practical cautions:
Round down, not up. Rounding a $3,246.00 ceiling to $3,250 is a $4 over-cap demand. Small in dollars — but the statute contains no de minimis exception.
Count increases already taken in the last 12 months. If you raised rent 4% in February 2026, you have 4.2% of headroom left in that window, not a fresh 8.2%.
Is Your Property Even Covered?
The 8.2% cap applies only to covered units. Several categories of San Diego rental housing are exempt:
- New construction. Housing issued a certificate of occupancy within the previous 15 years. This is a rolling exemption — a building exempt three years ago may not be exempt today. Re-verify annually.
- Single-family homes and condominiums, but only if (1) the property is not owned by a corporation, a REIT, or an LLC with at least one corporate member, and (2) the tenant received the statutorily required written exemption notice. Without the notice, the exemption does not apply regardless of ownership structure.
- Owner-occupied duplexes, where the owner has occupied one unit as their principal residence since the tenancy began.
- Deed-restricted affordable housing, dormitories, and certain owner-occupied share arrangements.
On the single-family exemption specifically: the required notice language must be delivered properly, and for tenancies entered into or renewed after July 1, 2020 it generally must appear in the lease itself. Owners who assume the exemption applies without confirming the notice was given are the ones who end up litigating it.
Properties inside City of San Diego limits are also subject to the City’s Residential Tenant Protections Ordinance (San Diego Municipal Code §§ 98.0701–98.0709), which imposes just cause requirements broader than state law, including protections that attach from day one of a tenancy. The City ordinance governs terminations rather than rent amounts — but it changes what happens if a tenant refuses the increase.
Notice Requirements
The rent cap and the notice statute are separate obligations. Civil Code § 827 requires:
- At least 30 days’ written notice where the increase, combined with any other increases in the prior 12 months, totals 10% or less.
- At least 90 days’ written notice where the increase exceeds 10%.
Because the statewide cap can never exceed 10%, covered units will effectively always fall in the 30-day category. Exempt properties can lawfully exceed 10% — and those increases require 90 days.
Notice must be served in a legally sufficient manner. Add five days if serving by mail.
Were Your Past Increases Lawful? Prior-Year Caps and Why They Still Matter
The cap resets every August 1, and each increase is measured against the cap in force on its effective date. That means an increase served in 2023 is judged by the 2023–2024 number, not today’s.
If you have held a unit through several increases — or acquired a property mid-tenancy and inherited someone else’s rent history — you need the full table:
| Effective Dates | San Diego County Cap |
|---|---|
| August 1, 2021 – July 31, 2022 | 9.1% |
| August 1, 2022 – July 31, 2023 | 10% |
| August 1, 2023 – July 31, 2024 | 10% |
| August 1, 2024 – July 31, 2025 | 8.6% |
| August 1, 2025 – July 31, 2026 | 8.8% |
| August 1, 2026 – July 31, 2027 | 8.2% |
The 10% figures in 2022–2023 and 2023–2024 reflect the statutory ceiling, not the formula. Regional inflation ran high enough in those years that 5% + CPI exceeded 10%, so the hard cap governed. A landlord who took 10% in those windows was within the law. A landlord who assumed 10% was permanently available and took it again in 2024–2025 was not — the cap that year was 8.6%.
Why an Old Over-Cap Increase Is Not a Closed Issue
Three consequences follow from an unlawful past increase, and the second and third are the ones that surprise people.
1. Direct exposure for the overage. The tenant may have a claim for the amount collected above the lawful maximum, discussed in the next section.
2. It corrupts the base rent going forward. Civil Code § 1947.12 measures the allowable increase against the lowest gross rental rate charged during the preceding 12 months. If a prior increase was unlawful, the argument follows that the lawful base was never the inflated figure — and every increase stacked on top of it compounds the original error. A single bad increase in 2023 can make three subsequent, individually reasonable-looking increases unlawful too. Compounding runs in the wrong direction here.
3. It can defeat an unlawful detainer. This is the practical risk that matters most. A three-day notice to pay rent or quit must state the amount of rent actually due. If the rent demanded includes an unlawful overage — even a small one — the notice overstates what is owed and is subject to challenge as defective. Landlords have lost otherwise-strong nonpayment cases on exactly this point, then had to start over with a corrected notice while arrears kept accruing.
If you are preparing to serve a notice on a long-term tenant, audit the rent history first. Discovering a 2023 miscalculation in your own files is inconvenient. Discovering it in a tenant’s answer is expensive.
How Far Back Does Liability Reach?
For rent cap claims, a tenant generally has three years from the date the cause of action accrued. Because liability can attach each time an over-cap payment is demanded or accepted, the practical reach can extend to the earliest over-cap payment still inside that window rather than to the date the increase was first served.
A further wrinkle: the enhanced remedies described below arrived with SB 567 and took effect April 1, 2024. Increases predating that date are governed by the prior framework, under which the primary consequence was that the excess was simply not owed. Whether and how the newer remedies apply to conduct that began before April 2024 but continued after it is a fact-specific question, and one worth asking a lawyer before you decide an old increase is safely behind you.
Running a Rent History Audit
For each unit with a tenancy predating August 2025:
- Pull every rent increase notice served during the tenancy, with its effective date.
- Match each one to the cap in force on that effective date using the table above — not the cap in force when the notice was drafted.
- Confirm the unit was covered in each of those years. The 15-year new-construction exemption rolls, so a unit may have been exempt in 2022 and covered by 2025. A unit that was exempt when an increase was taken is not measured against the cap at all.
- Check for stacking. Two increases inside one 12-month window must total no more than that window’s cap.
- Recalculate the lawful base rent forward from the first defective increase, if you find one.
- Decide on remediation before you serve anything new. Options generally include correcting the rent going forward, crediting or refunding the overage, and documenting the correction — but the right approach depends on the size of the discrepancy, how long it ran, and whether litigation is already in motion.
Self-correcting is almost always cheaper than being corrected. It also removes the defect from any notice you serve afterward.
What Non-Compliance Costs
Since SB 567 took effect in April 2024, the penalties for exceeding the cap are considerably sharper than they used to be.
An owner who demands, accepts, receives, or retains rent above the maximum allowable amount may be liable to the tenant for:
- Injunctive relief
- Damages equal to the amount by which the payment exceeded the lawful maximum
- Reasonable attorney’s fees and costs, at the court’s discretion
- Up to three times the excess amount, on a showing that the owner acted willfully or with oppression, fraud, or malice
The Attorney General, and the city attorney or county counsel where the unit is located, may also enforce the rent cap provisions and seek injunctive relief. Tenants have up to three years to bring a claim.
Note the structure carefully: liability attaches to demanding an over-cap rent, not only to collecting one. A defective notice can create exposure before a single dollar changes hands.
Compliance Checklist for August 1
- Confirm coverage. Is the unit exempt? If you’re relying on the single-family exemption, locate the notice in the lease file before you rely on it.
- Identify the CPI region. San Diego County is 8.2%. Properties elsewhere are not.
- Check the effective date. August 1, 2026 or later means 8.2%, regardless of when the notice was drafted.
- Subtract prior increases taken in the last 12 months.
- Audit the rent history on any tenancy that predates August 2025, and verify the current rent is a lawful base before you build on it.
- Round down.
- Serve proper notice — 30 days minimum for covered units, plus mailing time.
- Document everything. Keep the calculation, the notice, and proof of service together.
Frequently Asked Questions
What is the maximum rent increase in San Diego for 2026? 8.2% for any increase taking effect between August 1, 2026 and July 31, 2027, on properties covered by California’s Tenant Protection Act. This is calculated as the statutory 5% base plus the 3.2% San Diego regional CPI change.
Why did San Diego’s rent cap drop from 8.8% to 8.2%? Local inflation cooled. The formula is fixed at 5% plus regional CPI. San Diego’s CPI input fell from 3.8% to 3.2%, lowering the cap by the same 0.6 points.
I served a notice in July at 8.8%. Is it valid? Only if the increase takes effect on or before July 31, 2026. If the effective date falls on or after August 1, the increase is limited to 8.2%, and the notice should be corrected and re-served.
Can I raise rent twice in a year? Yes, but the combined increase across any 12-month period cannot exceed 8.2% on a covered unit.
Does the cap apply to my single-family rental? Possibly not — but only if the property is not owned by a corporation, REIT, or LLC with a corporate member, and the tenant received the required written exemption notice. Missing notice means the cap applies.
How much notice do I have to give? At least 30 days for increases of 10% or less; at least 90 days for increases above 10%. Covered units will always fall under the 30-day rule.
What were the San Diego rent caps in prior years? 9.1% for August 1, 2021–July 31, 2022; 10% for August 1, 2022–July 31, 2023; 10% for August 1, 2023–July 31, 2024; 8.6% for August 1, 2024–July 31, 2025; and 8.8% for August 1, 2025–July 31, 2026. Each increase is measured against the cap in force on its effective date.
I think I raised rent too much in a prior year. What happens now? Three things are in play: potential liability for the overage, the risk that the current rent is not a lawful base for future increases, and the possibility that a pay-or-quit notice stating the inflated amount would be defective. Have the rent history reviewed before serving any new notice.
Does an unlawful past increase make my current rent invalid? It can affect the lawful base. The statute measures each increase against the lowest rent charged in the preceding 12 months, so an unlawful increase can call into question the increases that were stacked on top of it. This is worth a professional review rather than a guess.
How far back can a tenant sue over an illegal rent increase? Generally three years from when the claim accrued, though the analysis is fact-specific — particularly for increases predating April 1, 2024, when the current remedies took effect.
What happens if I go over the cap? Potential liability for the excess amount, attorney’s fees, and up to treble damages for willful violations, plus enforcement action by public prosecutors.
Talk to a San Diego Landlord Attorney
Rent cap compliance is arithmetic until it isn’t. Exemption questions, mid-window increases, portfolios spanning multiple CPI regions, and City of San Diego ordinance overlays are where a defensible increase becomes a disputed one — and where a defective notice can undermine an unlawful detainer months later.
If you have questions about a specific increase, a tenant disputing one, or a notice you’ve already served, contact our office for a consultation.
This article is provided for general informational purposes and does not constitute legal advice. Rent cap figures reflect published CPI data as of July 2026 and are subject to annual reset each August 1.
