To report a rental property, you use two separate channels depending on the problem: local code enforcement for safety, building, or zoning violations, and the IRS for suspected unreported rental income. Knowing how to report a rental property to local government or the IRS starts with the same step in both cases, which is documentation. A vague complaint tends to sit; a specific one with dates, photos, and a named address gives an investigator something to work with.
Document the Problem Before You File
Get the property’s exact street address, including any unit numbers. County tax assessor websites are public and searchable by address, and they’ll show the legal owner’s name and mailing address. If the property is held by an LLC, the assessor’s records show the entity name, and state business filings may show more.
For safety or building concerns, photograph everything you can see: blocked exits, missing smoke detectors, exposed wiring, water damage, visible mold, overcrowded units. Write down the date and time next to each image. If the condition has persisted for weeks or months, a short log of repeated observations makes the complaint harder to dismiss as a passing dispute.
For suspected tax evasion, the useful evidence looks different. Estimate the rental income from what you can actually observe: how many units are occupied, comparable rents nearby, and how tenants pay. Cash-only payment, listings on rental platforms, and the absence of any lease paperwork are all worth noting. Save copies of any advertisements showing asking rents. The IRS doesn’t expect you to have the landlord’s bank statements, but grounded estimates beat a general accusation.
Reporting Code and Safety Violations Locally
Code enforcement complaints go to your city or county’s building, housing, or code enforcement department. Cities with a 311 system usually let you file by phone, website, or app, and those platforms accept photo uploads and issue a tracking number. Where no digital option exists, the building department in person works too. Ask for a case number as proof you filed.
After submission, the complaint gets logged, assigned to an inspector, and investigated. The inspector may contact the owner first to see if the issue can be resolved informally. If not, or if the violation is serious, the inspector issues a formal notice of violation with a deadline to fix the problem. Fines for unresolved residential code violations vary by jurisdiction but commonly run between $25 and $250 per day once the deadline passes. If the owner still ignores the notice, the case can escalate to an administrative hearing or court, where penalties accumulate and the municipality can seek an order compelling repairs.
Follow up using your tracking number. Code enforcement offices carry heavy caseloads, and a check-in every few weeks keeps your file active.
Anonymity When You File Locally
Most code enforcement offices accept anonymous complaints, but complaint records in many jurisdictions are public. Even if the complaint itself doesn’t name you, associated emails could be disclosed through a public records request. If anonymity matters, avoid filing from your personal email and ask the intake officer what information could become part of the public record.
Reporting Unreported Rental Income to the IRS
The reporting tool for suspected tax fraud is Form 3949-A, the Information Referral. The IRS now offers an online submission option, which is the fastest route.1Internal Revenue Service. About Form 3949-A, Information Referral You can also print the PDF and mail it to PO Box 3801, Ogden, UT 84409.2Internal Revenue Service. Form 3949-A – Information Referral
The form asks you to categorize the suspected violation. For landlords hiding rental revenue, the most relevant boxes are Unreported Income, Failure to File Return, and Failure to Pay Tax.2Internal Revenue Service. Form 3949-A – Information Referral Provide the owner’s name, address, and any identifying details you have. Include your best estimate of the unreported income, the time period, and how you believe the landlord receives payment. Attach copies of rental listings, advertisements, or lease documents that show the property is being rented commercially.
Submission is voluntary and confidential. You can file without providing your name, and the IRS keeps a reporter’s identity confidential.3Internal Revenue Service. 3.28.2 Information Referral Process for Form 3949-A Providing your contact information lets agents follow up for clarification, which can make the referral more useful during initial screening.
The IRS Whistleblower Program
If the unreported income is substantial and you want to seek a financial award, the IRS Whistleblower Office runs a separate track from the standard Form 3949-A. You file Form 211 under 26 U.S.C. § 7623.4Internal Revenue Service. Submit a Whistleblower Claim for Award
There are two tiers. Mandatory awards apply when the tax, penalties, and interest in dispute exceed $2 million. If the taxpayer is an individual, their gross income must also exceed $200,000 in at least one relevant tax year.5Internal Revenue Service. 25.2.2 Whistleblower Awards A successful mandatory claim pays between 15% and 30% of the amount the IRS collects, depending on how much the whistleblower’s information contributed.6Office of the Law Revision Counsel. 26 USC 7623 – Expenses of Detection of Underpayments and Fraud, Etc.
For cases below those thresholds, the IRS has discretion to pay a smaller award, capped at 10% of the proceeds. The 10% cap also applies when the whistleblower’s information merely supplemented what was already known from public records or news reports.6Office of the Law Revision Counsel. 26 USC 7623 – Expenses of Detection of Underpayments and Fraud, Etc. If the whistleblower was personally involved in planning the tax evasion, the award can be reduced or denied entirely.
Most single-landlord rental cases won’t hit the $2 million threshold, but the discretionary track still allows awards on smaller cases. An operation with dozens of unreported units or years of evasion can add up faster than expected.
What Happens After You Report
Local Code Enforcement
Timelines depend on how serious the violation is and how busy the office is. An inspector typically visits the property after the complaint is assigned, usually without disclosing who filed. If violations are confirmed, the owner receives a notice with a deadline to correct. Immediate hazards, such as missing smoke detectors or exposed wiring, get faster attention than aesthetic or zoning complaints.
If the landlord ignores the notice, daily fines start to accrue and the case moves toward an administrative hearing. Your documentation becomes central at that stage, because the landlord’s usual defense is that the issues were already fixed or never existed.
IRS Tax Investigations
The IRS does not send status updates to people who file standard Form 3949-A referrals. Federal law under 26 U.S.C. § 6103 makes return information confidential, so the IRS cannot tell you whether it audited the landlord, what it found, or what penalties were imposed.7Office of the Law Revision Counsel. 26 USC 6103 – Confidentiality and Disclosure of Returns and Return Information You file and then hear nothing. That’s normal, not a sign the referral was ignored.
Form 211 whistleblowers get more visibility. The IRS is required to notify a whistleblower within 60 days after the case is referred for audit, and again within 60 days after the taxpayer makes a payment tied to the whistleblower’s information.7Office of the Law Revision Counsel. 26 USC 6103 – Confidentiality and Disclosure of Returns and Return Information Whistleblowers can also request status updates and, if they disagree with the award determination, have 30 days to appeal to the Tax Court.6Office of the Law Revision Counsel. 26 USC 7623 – Expenses of Detection of Underpayments and Fraud, Etc.
Anti-Retaliation Protections if You’re a Tenant
Tenants who report code violations often worry about eviction, rent hikes, or reduced services in return. Roughly 42 states have laws making that kind of retaliation illegal. The usual mechanism: if a landlord takes adverse action shortly after a tenant reports a violation to a government agency, the law presumes the action was retaliatory. Some states set a specific window. In California, any adverse action within 180 days of a complaint or inspection request is presumed retaliatory.
Prohibited retaliatory actions generally include eviction, rent increases, reducing maintenance or services, refusing to renew a lease, and threats of legal action. Idaho, Indiana, and Wyoming have no statute on the books addressing retaliatory eviction, though their courts may still recognize it as a defense under common law.
Before filing, check whether your state recognizes retaliation as a defense. Where protections exist, save a copy of your complaint, note the date you filed, and keep records of any changes in the landlord’s behavior afterward. That timeline is the strongest evidence if you later need to raise retaliation as a defense.
The Risk of a False Report
Knowingly filing a false report carries real consequences. Most states make it a criminal offense to provide false information to law enforcement or a government agency, typically a misdemeanor that can bring fines, restitution for the cost of the investigation, and possibly jail time. A landlord who can show the report was deliberately false and damaging can also pursue a civil defamation claim.
The threshold is knowing falsity, not being mistaken about what you saw. If you reasonably believe a violation exists and document your observations honestly, you’re on solid ground even if the investigation doesn’t confirm every detail.