The ADU move-out: deposits, the 21-day clock, and what you can deduct

Fall turnover season starts about now, and every year I get the same call in early October from an owner whose tenant moved out in September. They kept a chunk of the deposit for cleaning and a scuffed wall, they sent the tenant a note about it six weeks later, and now there's a demand letter. The frustrating part is that they were probably entitled to some of what they kept. They just lost the right to it on a deadline.

Twelve years managing ADUs across the South Bay, 200-plus tenancies, and the move-out is where I see self-managing owners lose money on pure procedure. Here's how the deposit rules actually work.

The 21-day clock is the whole ballgame

After the tenant moves out and returns possession, you have 21 calendar days to either return the full deposit or deliver an itemized statement accounting for every deduction, along with any remaining balance.

Twenty-one calendar days, not business days. Not from when you get around to inspecting. From move-out.

Miss it and the consequence is severe: a landlord who fails to provide a proper, timely itemized statement forfeits the right to keep any of the deposit. Not the disputed portion. All of it. Even deductions you could have fully justified.

That single rule is responsible for most of the deposit disputes I get called into. The owner had a legitimate claim and blew the deadline.

What changed on the cap

The amount you can collect up front changed in 2024 and a lot of ADU owners are still working off the old rule.

For leases entered into, renewed, or extended on or after July 1, 2024, the general cap is one month's rent, furnished or unfurnished. That replaced the old two-months-unfurnished, three-months-furnished structure.

But there's a small-landlord exemption, and most ADU owners fall inside it. If you're a natural person, an LLC whose members are all natural persons, or a family trust, and you own no more than two residential rental properties containing no more than four total units, you can still collect up to two months' rent. A homeowner with one ADU in the backyard is squarely within that.

One carve-out that matters: the exemption does not apply if your tenant is an active-duty service member. In that case the cap is one month, full stop.

Given the furnished mid-term tenants a lot of South Bay ADU owners take, the furnished-versus-unfurnished distinction disappearing from the cap is worth knowing. You're not entitled to more just because the unit came with furniture.

New for 2026: electronic return

Effective January 1, 2026, landlords must offer electronic return of the deposit where the tenant paid rent or the deposit electronically. If your tenant Zelled you the deposit and you want to mail a paper check to a forwarding address, you now need to at least offer the electronic option.

Small change, easy to miss, and it's the kind of procedural detail that gets raised in a dispute.

What you can deduct, and what you can't

Four categories are deductible: unpaid rent, cleaning to return the unit to the level of cleanliness it had at move-in, repair of damage beyond normal wear and tear, and restoration or replacement of personal property where the lease allows it.

The phrase doing the work is beyond normal wear and tear, and owners consistently read it too broadly.

Normal wear and tear, generally not deductible: minor scuffs on walls, small nail holes, carpet that's worn along traffic paths, faded paint, a few loose grout lines, minor wear on countertops and fixtures. This is the cost of renting a unit to a human being for two years.

Beyond normal wear and tear, generally deductible: large holes, pet damage, burns or deep stains in carpet, broken fixtures or appliances, unauthorized paint colors, and genuine filth requiring more than a standard turnover clean.

The distinction that trips people: you cannot charge a tenant to bring the unit to a *better* condition than they received it. If the carpet was five years old at move-in and it's seven years old now, that's depreciation, not damage. Repainting a unit on a normal repaint cycle is a cost of ownership, not a deduction.

The pre-move-out inspection

California gives the tenant the right to request an inspection before they move out, and you're required to notify them of that right. If they request it, you inspect, and you give them an itemized list of what you'd currently deduct so they have a chance to fix it themselves.

Owners hate this because it feels like handing over leverage. In practice it's the single best dispute-avoidance tool available. A tenant who patches the holes and deep-cleans the oven costs you nothing, and a tenant who saw the list in advance almost never disputes the final statement.

I offer it on every tenancy, whether or not it's requested.

Documentation that survives

What actually holds up when a deposit is contested:

Move-in condition documentation with dated photos of every room, closet, appliance, and any pre-existing damage, signed by the tenant. Without this, you have no baseline and almost any dispute goes against you. The screening and lease process is where this starts, not the move-out.

Move-out photos from the same angles, dated.

Actual invoices and receipts for any work you deduct. California requires you to attach documentation for repairs and cleaning in the itemized statement, and estimates are weaker than invoices. If you did the work yourself, you can charge reasonable value for your time, but describe it specifically.

A copy of the itemized statement and proof of when you sent it. Certified mail or a dated email both work; the point is being able to prove the 21 days.

The move-out sequence I run

Roughly 30 days out, send the move-out instructions with the cleaning expectations and the notice of the right to a pre-move-out inspection.

Two weeks out, do the pre-move-out inspection if requested and give the itemized list of anticipated deductions.

Move-out day, collect keys, confirm the forwarding address, and walk the unit with the camera.

Within a few days, get vendors in for cleaning or repairs so you have real invoices rather than estimates.

Well inside 21 days, send the itemized statement with receipts and the balance, using the tenant's preferred return method.

Turning the unit for the next tenant runs in parallel, and the fall timing matters: a unit back on market by mid-September leases materially faster than one that sits until November.

What to do this month

• Put the 21-day deadline on a calendar the day a tenant gives notice, not the day they leave
• Check whether you qualify for the small-landlord exemption before setting the deposit on your next lease
• If your tenant pays electronically, plan to offer electronic return
• Pull your move-in photos now and confirm you actually have them
• Offer the pre-move-out inspection even if the tenant doesn't ask
• Get invoices, not estimates, before you write the statement

The deposit rules aren't hard, but they're unforgiving on timing and documentation, and the penalty for sloppiness is losing money you were owed. Most of the disputes I see were preventable with a calendar reminder and a folder of photos.

I manage properties, I'm not an attorney, and this is general information rather than legal advice for your situation. If a deposit dispute is already in motion, talk to a landlord-tenant attorney rather than improvising.

Turning over an ADU this fall and want it re-leased quickly at the right rent? Request a free ADU rental analysis and I'll walk through the turn and the pricing. Or call me at (408) 813-8001.

Sources

• California Civil Code Section 1950.5 (Security Deposits) — California Legislative Information
• California AB 12 (2023) — security deposit limits — California Legislative Information
• New law limiting security deposits — California Apartment Association
• California Tenants Guide (landlord/tenant rights) — California Department of Consumer Affairs
• California Courts — Security Deposits and Small Claims — Judicial Council of California
• California Civil Rights Department — California Civil Rights Department