Wisconsin Small Claims Court Security Deposit: How to Sue Your Landlord

The 21-Day Rule and What Triggers a Claim

Under Wis. Admin. Code ATCP 134 and Wis. Stat. § 704.28, if you move out at the end of your lease, the landlord has 21 days after you move out to return your deposit or provide a written itemized statement of deductions. If you leave before the lease ends, the 21-day period starts on the earlier of the last day of the lease or the date a new tenant moves in.

If the landlord does not return or mail the deposit or an itemized statement within the applicable 21-day period, they may have violated the rule. The statement must describe each deduction and the amount withheld; the landlord is not required to attach receipts or invoices. You can challenge a deduction you believe is improper.

Before you do anything else, send a written demand. Mail it by certified mail or USPS first-class with a certificate of mailing so you have proof. Give the landlord 14 to 30 days to respond. If they ignore the demand or refuse to pay, that letter becomes the first exhibit in your court file.

Double Damages for ATCP 134 Violations

Wisconsin is one of the states where you can recover more than the deposit itself. If a violation of Wis. Admin. Code ATCP 134 causes you pecuniary loss, Wis. Stat. § 100.20(5) provides for twice the amount of that loss, plus costs and reasonable attorney fees. The statute does not make bad faith a prerequisite. As one Madison renter posted after winning their case: "the judge awarded him 2x the total security deposit plus court costs."

How to File the Claim

Security deposit disputes are contract claims, so the $10,000 small claims cap applies (rising to $15,000 on January 1, 2027). Most security deposits fall well under that limit.

Here is the sequence:

1. Verify the landlord's legal name. If your landlord is an LLC or corporation, search the Wisconsin Department of Financial Institutions (DFI) database at dfi.wi.gov. File against the registered entity name — not the property's DBA or marketing name. Suing the wrong entity can get your case dismissed.

2. Complete Form SC-500 (Summons and Complaint). Check the "Money Judgment" box. In the factual statement, lay out: move-in date, deposit amount, move-out date, demand letter date, and what the landlord failed to do within 21 days.

3. File at the Clerk of Circuit Court in the county where you rented (venue for contract disputes lies where the cause of action arose). Total filing cost is roughly $94.50, plus $2–$15 for clerk-mailed service where local rules allow and the defendant resides in the county.

4. Serve the landlord at least 8 business days before the return date. Clerk mail service may be used only where local rules allow and the landlord resides in the county. If the landlord is an LLC, serve the DFI-registered agent.

If you cannot afford the filing fees, Form CV-410A (Petition for Waiver of Fees and Costs) lets you apply for a full waiver.

What to Bring to the Hearing

Organize three copies of each exhibit — one for the judge or commissioner, one for the landlord, one for yourself. Wisconsin small claims hearings use relaxed evidence rules under Wis. Stat. § 799.209, but organized exhibits still carry more weight.

Your evidence checklist:

• Lease agreement showing the deposit amount and move-in date
• Move-out documentation: photos or video of the unit's condition when you left, timestamped if possible
• Move-in photos for comparison (if you have them)
• Demand letter and proof of mailing (certified mail receipt or certificate of mailing)
• Any communication from the landlord — texts, emails, letters — about deductions or refusal to return the deposit
• Bank records showing the original deposit payment
• Forwarding address proof: evidence you gave the landlord a forwarding address (the landlord cannot claim they had nowhere to send the check)

If the landlord sent a deduction statement, bring it and be ready to challenge specific line items. Deductions for normal wear and tear are not allowed — only actual damage beyond ordinary use.

After the Hearing

If the commissioner rules in your favor, the landlord has 10 calendar days (oral decision) or 15 calendar days (written decision) to demand a trial de novo before a circuit court judge. If they do not, the judgment stands.

Collecting the money is a separate process. If the landlord does not pay voluntarily, the Wisconsin Small Claims Judgment Collection Guide covers enforcement tools like wage garnishment and bank levies.

For the complete filing process — demand letter through hearing — the Wisconsin Small Claims Filing Guide walks through every form, fee, and deadline in order.

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