California Tenant Security Deposit Calculator

How this calculator works

California residential security deposits are governed by Cal. Civil Code § 1950.5, which was materially overhauled by AB 12 (Statutes of 2023, Ch. 689) with an effective date of July 1, 2024. AB 12 is the largest California landlord-tenant deposit reform in more than thirty years: the prior framework — two months' rent for unfurnished units, three months' rent for furnished units — was compressed to a single month's rent for most residential leases. The calculator projects a California deposit dispute end-to-end against the post-AB-12 statute: the lawful maximum deposit under the § 1950.5(c) cap, whether the deposit charged complies, the § 1950.5(g)(1) 21-day return deadline, the § 1950.5(g)(2) itemized statement and $125 receipt threshold, and the § 1950.5(l) bad-faith retention exposure.

The post-AB-12 cap — § 1950.5(c)

Under the post-AB-12 framework, the deposit cap operates on a two-axis lookup keyed to landlord classification and tenant status:

• Default rule (§ 1950.5(c)(1)). One month's rent. Applies to virtually every California residential lease regardless of furnished status.
• Small-landlord exception (§ 1950.5(c)(4)). Two months' rent if the landlord is a natural person (or an LLC where every member is a natural person) AND owns no more than two residential rental properties comprising no more than four total dwelling units. Both conditions must be met simultaneously. Institutional landlords (REITs, large property managers, corporate lessors) never qualify regardless of unit count.
• Active-duty servicemember protection (§ 1950.5(c)(5)). One month's rent regardless of landlord type. The servicemember protection overrides the small-landlord exception — an active-duty servicemember tenant gets the one-month cap even if the landlord otherwise qualifies for the two-month bucket.

This is a meaningful change from pre-AB-12 California. A typical $3,000-rent unfurnished San Jose apartment that previously carried a $6,000 deposit (two months') is now capped at $3,000 (one month) unless the landlord meets the strict small-landlord test. For a furnished West Hollywood unit at the same rent, the pre-AB-12 cap was $9,000 (three months); the post-AB-12 cap is $3,000 — a two-thirds reduction in upfront move-in costs.

Worked example — illegal deposit on standard landlord

A tenant signs a one-year lease on a $3,000-per-month San Diego apartment with a corporate property-management landlord. The landlord charges a $5,000 security deposit. Under § 1950.5(c)(1), the lawful maximum is $3,000 (one month's rent). The deposit is $2,000 over the cap. The corporate landlord cannot claim the § 1950.5(c)(4) small-landlord exception. The tenant should send a written demand citing § 1950.5(c) for return of the $2,000 excess; continued retention exposes the landlord to a § 1950.5(l) bad-faith finding with statutory damages of up to two times the deposit ($10,000) plus actual damages. The strategic read: the landlord's $2,000 excess is at risk of becoming a $10,000+ statutory penalty plus attorney's fees.

Worked example — lawful deposit on small landlord

A tenant signs a lease on the same $3,000-per-month apartment, but this time the landlord is an individual who owns two duplexes (four total units) and self-manages. The landlord qualifies under § 1950.5(c)(4) — natural person, two properties, four total units. The lawful maximum is $6,000 (two months' rent). A $5,000 deposit is lawful, and a $6,000 deposit is the absolute ceiling. The same $5,000 deposit that violates § 1950.5(c) when charged by the corporate landlord above is fully compliant here. The small-landlord exception is among the most-litigated facets of AB 12's first year — landlords who incorrectly self-classify as "small landlords" face a § 1950.5(l) bad-faith finding even though the deposit amount looks reasonable on its face.

Worked example — itemized deductions and the $125 threshold

A tenant on a $2,500-per-month lease vacates with the unit moderately worn. The landlord claims $1,800 in deductions: $800 for carpet cleaning, $600 for wall repair, $400 for unpaid utilities. The deposit is $2,500. Under § 1950.5(g)(1), the landlord must return the $700 balance within 21 days. Under § 1950.5(g)(2), because total deductions ($1,800) exceed the $125 threshold, the itemized statement must be accompanied by receipts, invoices, or good-faith estimates for the work — not just an itemized list. A landlord who sends a list of three line items without receipts is procedurally noncompliant even if every charge is substantively valid. The tenant should demand the receipts in writing; failure to produce them supports a § 1950.5(l) bad-faith finding on the deductions.

Worked example — bad-faith retention

A tenant on a $2,500-per-month lease vacates and the landlord does not return the deposit or send an itemized statement at all. Twenty-one days pass, then thirty. The deposit is $2,500. Under § 1950.5(g)(1), the deadline was missed. Under § 1950.5(l), the tenant may recover the $2,500 deposit plus statutory damages up to $5,000 (two times the deposit) plus any actual damages. The phrase "treble damages" sometimes used to describe § 1950.5(l) is a common misstatement — the California statute is 2x, not 3x. The bad-faith standard is fact-specific; the landlord's failure to send any itemization within 21 days is the single most reliable predictor of a successful bad-faith finding.

The § 1950.5(f) walkthrough right

Cal. Civ. Code § 1950.5(f) gives the tenant the right to request a pre-move-out inspection no earlier than two weeks before the end of the tenancy. The landlord must provide an itemized statement of proposed deductions — the same form of statement required at move-out — so the tenant can cure deficiencies (clean the unit, repair minor damage, replace a missing fixture) before the final inspection. Tenants who exercise the walkthrough right substantially reduce post-move-out deductions; landlords who refuse to schedule the inspection face § 1950.5(l) bad-faith exposure on any subsequent deduction claims for items the tenant could have cured. The walkthrough right is one of the most underused tenant-protection mechanisms in California residential practice — under 20% of California tenants request it according to legal-aid surveys, even though it routinely saves several hundred dollars per move-out.

Local interest ordinances — not statewide

California has no statewide statutory requirement to pay interest on residential security deposits. However, approximately fifteen California cities require interest under local rent ordinances:

• San Francisco (Admin. Code § 49.2) — interest paid annually at a rate reset each year by the Rent Board.
• Berkeley (Rent Ordinance § 13.84.030) — annual interest on deposits held more than one year.
• Los Angeles (LARSO § 151.06.02) — interest required on deposits in rent-stabilized units.
• Santa Monica, West Hollywood, East Palo Alto, Hayward, and several others — local-ordinance rates that vary annually.

The covered cities and their rates change; verify the current rate with the local rent board at lease end. This calculator surfaces the local-interest issue without computing it because the rate is city-specific and rest annually — the right place to look the number up is the local rent board's annual interest notice.

Pet deposits, last-month's rent, and the cap

Cal. Civ. Code § 1950.5(b) defines "security" broadly to include any payment, fee, deposit, or charge imposed at the inception of the tenancy or during it to secure performance of the lease. Pet deposits, key deposits, redecorating fees, and last-month's-rent prepayments all count toward the § 1950.5(c) cap. The only common payments that do not count are application fees (capped separately under § 1950.6) and screening fees. A landlord charging $3,000 rent plus a separate $3,000 "pet deposit" on a one-month-cap tenancy is over the cap by $3,000 even though each line item looks reasonable in isolation. This is the most-common drafting error in California residential leases written post-AB-12 — the lease silos the pet deposit out as if it were a separate category, but the statute aggregates everything.

Common errors

• Treating § 1950.5(l) damages as treble. The statute is two times the deposit, not three. Plaintiff's counsel routinely overstates the ceiling in demand letters; opposing counsel correctly recognizes the misstatement and discounts the demand.
• Missing AB 12 on a pre-July-2024 lease analysis. Leases signed before July 1, 2024 are governed by pre-AB-12 law; leases signed on or after July 1, 2024 are governed by the post-AB-12 cap. The transition date is the lease execution date, not the move-out date.
• Miscounting servicemember status. Active-duty servicemember status under § 1950.5(c)(5) means active orders during the tenancy — not veteran status, not retired military, not Reserves who are not on activated orders.
• Conflating the § 1950.5(c) cap with the § 1950.5(g) return-deadline failure. These are independent violations. An over-cap deposit that is timely returned still violates § 1950.5(c). A within-cap deposit that is not returned within 21 days still violates § 1950.5(g)(1). Both can compound.

What the calculator does not do

This is a planning and verification tool. It does not:

• Replace litigation counsel. California security-deposit practice involves substantive judgment on the bad-faith standard, the wrongful-withholding count, the attorney-fee posture under fee-shifting cases, and the local-ordinance interest math. Consult a California-licensed attorney for the specific case.
• Compute local-ordinance interest. SF, Berkeley, LA, Santa Monica, West Hollywood, and the other covered cities each set their own rates, reset annually. Look the current rate up with the local rent board.
• Address commercial deposits. Commercial leases are governed by general California contract law, not § 1950.5; most commercial leases displace any default rule with lease-specific deposit provisions enforceable as written.
• Handle mobile-home park deposits. Mobile-home park tenancies are governed by the California Mobilehome Residency Law (Civil Code §§ 798–799.11) with their own deposit rules; § 1950.5 does not apply.

How this page is maintained

The post-AB-12 framework of § 1950.5 has been in force since July 1, 2024 and is settled California law. We monitor each California legislative session for amendments to § 1950.5 and any appellate decision interpreting the post-AB-12 cap, the small-landlord exception, the 21-day return deadline, or the § 1950.5(l) bad-faith standard. The page is refreshed within the quarter after any statutory or material case-law change.

Last reviewed: 2026-05-15 against Cal. Civ. Code § 1950.5 and AB 12 (Stats. 2023, Ch. 689).