California FTB Audits: Procedures, Deadlines and Representation

Understanding California FTB Audits

A California FTB audit reviews tax returns and records to determine the correct California tax and any applicable interest or penalties. The process may result in no change, a proposed assessment, an overassessment or an adjustment to a carryover. An audit notice does not itself establish that additional tax is owed.

California assessment, protest and collection procedures differ from federal procedures. Identify the agency, notice type and response deadline before deciding what to do. Collection measures and license consequences have separate legal requirements; they are not automatic results of being audited.

The FTB conducts desk and field audits. It may also propose an assessment using available information when a required return is not filed, and federal adjustments may require a separate California response. These situations do not all follow an identical process.

California FTB audits: Review the relevant notices, filing history, records, and deadlines before choosing a response. Evaluate professional assistance according to the facts, applicable law, and agreed scope of representation.

The Anatomy of A California FTB Audit

The FTB reviews available tax information when deciding whether to accept a return as filed or open an audit. Selection alone does not prove that the return is incorrect.

How the FTB Selects Taxpayers for an Audit

The FTB describes reviewing federal and state returns, prior audit history, exclusions and deductions, public information, and IRS data. These are documented sources of information, not a published formula for predicting whether a particular return will be audited.

Transactions such as like-kind exchanges, losses passed through from businesses and sales of investments may require detailed supporting records. Their presence on a return does not establish a particular audit probability or an error.

A discrepancy should be checked against the return, underlying records and applicable law before accepting a proposed adjustment. Learn what a tax audit involves.

Audit Methods and Other Assessment Situations

The notice should explain what the FTB is reviewing and what it needs from you. The auditor selects an audit method based on the return and practical access to records.

Desk audits: Usually handled through correspondence and secure email. The FTB requests records for the issues under examination.
Field audits: Conducted where records can be examined, often at a home or business. An FTB office or a representative’s office may be appropriate. A field audit does not by itself establish wrongdoing.
Nonfiling assessments: If a required return is not filed, the FTB may estimate net income from available information and propose tax, interest and applicable penalties. Review the estimate and provide the required return and supporting records as appropriate; an estimate is not necessarily inflated.
Federal adjustments: An IRS change may affect California tax, subject to state law. Required federal changes generally must be reported to the FTB within six months of the final federal determination. Do not assume IRS information sharing satisfies your own reporting obligation.

Checking Information Against Your Records

Compare the items identified by the auditor with your filed returns and source documents. Explain differences clearly, including any California adjustments to federal figures. If requested records are unavailable, discuss possible alternative evidence with the auditor.

FTB examinations review returns and supporting information. Selection methods do not determine whether a particular taxpayer owes additional tax or qualifies for relief.

FTB vs. IRS Audits: Key Differences You Must Know

An FTB audit applies California law, while an IRS audit applies federal law. Both agencies have procedures for examining records and challenging proposed changes. Their deadlines and remedies should be evaluated separately.

Feature	California FTB Audit	IRS Audit
Primary Focus	California state income tax laws	Federal income tax laws
Data Sources	State and federal returns, prior audit history, public information and IRS data	Tax returns, books, accounts and financial records
Audit Selection	Review of returns and supporting information under FTB procedures	Random selection, computer screening and related examinations
Representation	Self-representation or an authorized representative; use the applicable FTB POA declaration	Self-representation or an authorized representative under IRS procedures
Collection Powers	Liens and withholding orders or levies under applicable procedures; separate Top 500 license rules	Liens and levies, including wages or property, under federal collection procedures
Ordinary Assessment Period	Generally 4 years to mail a proposed deficiency notice after filing; early-filed returns are generally treated as filed on the original due date. Exceptions apply.	Generally 3 years to assess tax after filing or the return due date, whichever is later. Exceptions apply.
Examples of Issues Requiring Records	Residency, 1031 exchanges, flow-through entity losses, capital gains, state-specific NOL rules	International tax, complex corporate structures, large individual deductions

Collection Powers and Their Limits

Respond to FTB requests according to the notice and preserve applicable protest and appeal deadlines. Comparative descriptions of agency aggressiveness do not establish legal rights or liabilities.

California publishes a statutory list of the 500 largest qualifying tax delinquencies exceeding $100,000, subject to notice requirements and exclusions. For taxpayers on a certified list, applicable licensing agencies may suspend covered professional or occupational licenses, and the DMV may suspend a driver’s license, under Business and Professions Code section 494.5. The statute includes advance notice, release procedures and exceptions. These consequences do not apply to every unpaid balance.

The right response depends on the actual notice and the dispute. A qualified adviser can help identify the applicable state procedures. Federal procedures are discussed separately in our IRS audit defense guide.

Issues That May Require Supporting Records

The following topics can involve California-specific rules. They are examples to review, not a ranking of audit probabilities.

Residency status: Keep records relevant to your domicile, time in California and reasons for being inside or outside the state. Moving or changing an address does not by itself resolve residency under California law.
1031 like-kind exchanges: Review eligibility and documentation under the rules for the exchange year. For taxable years beginning on or after January 1, 2025, California limits like-kind exchanges to real property. An exchange of California property for out-of-state property may also require annual Form FTB 3840 reporting of deferred California-source gain or loss.
Losses from flow-through entities: Records may be needed to support losses from S corporations, partnerships or LLCs, including applicable basis, at-risk and passive-activity limitations.
Capital gains and losses: Reconcile reported sales, proceeds, adjusted basis and any California adjustments for investment transactions, including stock and digital-asset dispositions. Retain records supporting the treatment claimed.
Delinquent returns: Determine whether a filing obligation exists and respond to filing demands. The FTB may propose tax using available information when a required return is missing.
Nonresident California income: A nonresident may still have California-source income and a California filing obligation. Apply the sourcing and filing rules to the particular income, including after a move. Read more about residency and California taxation.

Your Step-by-Step Guide to Responding to an FTB Audit

Receiving an audit notice can be stressful. Organizing the notice, deadlines and supporting records helps you prepare a clear response.

Step 1: Receiving the Notice and Initial Preparation

An Initial Contact Letter identifies the audit and provides contact information. Read it for the years, issues, requested records and response dates. Verify an unexpected notice through official FTB channels. You may contact the auditor to clarify a request or arrange an appointment, and you may seek professional advice before discussing substantive issues.

Gather and preserve the records supporting the items under review. Provide accurate, responsive information and explain discrepancies without guessing. If a request is unclear or records are missing, discuss the scope or possible alternatives; do not conceal required information. Keep copies of what you send. Read more about business tax audits.

Step 2: Understanding Your Rights and Getting Representation

You have rights during a California FTB audit, including fair treatment, representation and the opportunity to challenge proposed adjustments through applicable procedures. Read the California Taxpayers’ Bill of Rights information (FTB 4058).

You may represent yourself or appoint an authorized representative, such as a certified public accountant, enrolled agent or tax attorney. Use FTB 3520 PIT for an individual or fiduciary, or FTB 3520 BE for a business entity or group nonresident matter. A POA declaration can be submitted through MyFTB or on paper; the representative’s authority depends on its scope. Consider the issues, qualifications and agreed services when choosing assistance.

Step 3: Navigating the Audit Process

Whether you respond yourself or through a representative, the audit may include the following steps:

Opening conference: The auditor may hold one, or you may request one, to discuss the issues, communications, records and anticipated schedule. Audit plans are more common in multistate audits.
Information Document Requests (IDRs): Review each request and its response date. Supply supporting records or discuss alternative evidence if records are unavailable. Unanswered requests may lead to a formal demand and other consequences under applicable law.
Audit Issue Presentation Sheet (AIPS): The auditor may use this to explain the facts, law and proposed treatment of an issue. Review it and provide relevant corrections, explanations and evidence.
Status and closing conferences: A status discussion may help address delays or unresolved issues. At closing, the auditor explains findings and applicable rights; the discussion may occur in person, by phone or in writing.

For more detail, you can review the FTB’s internal procedures: View the FTB’s Manual of Audit Procedures (MAP)

Step 4: Understanding the Potential Outcomes

An audit can end in several ways:

No-change result: The FTB accepts the return as filed, with no additional tax from that audit. This does not erase an existing unpaid balance or resolve unrelated periods.
Notice of Proposed Assessment (NPA): This proposes additional tax and any applicable penalties and interest. Review the calculation and protest deadline; a proposal is not yet a final assessment.
Notice of Overassessment or Proposed Overassessment: This indicates an overpayment or proposed reduction. Any refund or credit remains subject to applicable claim, offset and other rules.

An audit may also adjust a carryover, such as a loss or credit available in another year, without changing the current year’s tax. Review the effect on other returns.

After the Audit: Protests, Appeals, and Consequences

An NPA gives you an opportunity to challenge a proposed assessment through the protest process. Preserve the deadline even if you are still gathering records or arranging representation.

Disagreeing with the Results: The Protest and Appeal Process

A written protest generally must be filed within 60 days after the NPA is mailed. Follow the protest-by date and filing instructions on the notice; R&TC section 19041 also treats a protest filed by the date specified by the FTB as timely. Identify the disputed amounts and years, grounds for disagreement and supporting facts, law and records.

After considering the protest, the FTB issues a Notice of Action (NOA) affirming, revising or withdrawing the proposed assessment. An adverse NOA generally may be appealed to the Office of Tax Appeals (OTA) within 30 days of its date; follow the appeal-by date and instructions. A later refund lawsuit has separate prerequisites: generally full payment, a timely administrative refund claim, and satisfaction of the applicable denial or waiting-period rules. Court filing deadlines depend on the procedural route, and residency cases have special rules. Paying after an OTA decision does not by itself complete those steps.

A qualified representative can help evaluate the record, legal grounds and procedural choices. Federal disputes use different procedures; our guide to disagreeing with an IRS audit addresses that separate context.

Understanding the Statute of Limitations (SOL)

California’s ordinary deficiency limitation governs when the FTB may mail a proposed deficiency notice. It is different from the deadline to protest and from the period for collecting an assessed debt.

The general rule is four years after the return is filed. A return filed before its original legal due date is generally treated as filed on that date, without regard to a filing extension. Other statutory extensions and exceptions may apply.
If a required return is not filed, the ordinary four-year period does not begin. The FTB may propose an assessment at any time under the nonfiling rules. Fraudulent returns filed with intent to evade tax also have special rules.
Federal adjustments have separate rules. Report required changes within six months after the final federal determination. Timely reporting generally gives the FTB two years from receipt of the report, or the otherwise applicable period if later, to mail a notice arising from those changes. Late reporting can give four years from receipt; absent the required report, the period can remain open for the resulting adjustment. This does not automatically reopen every unrelated issue. Read R&TC section 18622.

The FTB may request written consent to extend an assessment period. Before agreeing, review the proposed expiration date, covered issues and consequences of accepting or declining; professional advice may help assess that choice.

Consequences of Missing Requests or Deadlines

Failing to respond can leave the FTB to decide an issue on the available record and can cause you to lose a timely protest or appeal opportunity. The consequences depend on the request, notice and governing law.

Demand penalty: R&TC section 19133 can apply to failure or refusal to provide information requested in writing, or to file a required return after notice and demand. Its 25% rate applies to the tax determined under section 19087 or the related deficiency tax specified by the statute. The statutory exception requires reasonable cause and absence of willful neglect. The penalty is not automatic for every delayed document response.
Collection: An unpaid assessed liability may lead to a tax lien, bank levy or withholding from wages under applicable procedures. Notice requirements, exemptions and available collection remedies must be considered separately from the audit.
License consequences require the applicable statutory process, including qualifying Top 500 delinquency-list criteria and prior notice. They do not follow automatically from ignoring any audit request.
Unsupported return items: The FTB may disallow deductions or other items that are not substantiated and may propose adjustments based on available information. Review the calculations; nonresponse does not establish that an estimate is necessarily inflated.

Timely, accurate responses preserve opportunities to explain the facts and challenge proposed changes. Professional assistance may help, but it does not guarantee that tax, interest, penalties or collection consequences will be eliminated.

Frequently Asked Questions about FTB Audits

These questions address common procedural issues in a California FTB audit.

What is the general statute of limitations for a California FTB audit?

Generally, the FTB has four years to mail a proposed deficiency notice after the return is filed, with early-filed returns generally treated as filed on the original due date. R&TC section 19058 allows six years when an omission from gross income exceeds 25% of the gross income stated on the return, subject to its definitions and disclosure rules. Nonfiling, fraud, federal adjustments, written extensions and other statutory rules can alter the period. The deadline must be evaluated for the particular issue and year. Read the federal-adjustment reporting law.

What happens if I don’t respond to an FTB audit notice?

The FTB may proceed using available information, disallow unsupported items or issue a proposed assessment. Missing a protest or appeal deadline can make an assessment final. A demand penalty requires its own statutory conditions and reasonable-cause analysis; it does not attach automatically to every late response. Follow the actual notice and seek clarification promptly if needed.

Can I represent myself in an FTB audit?

Yes. You may represent yourself or appoint an authorized representative. Consider the complexity of the issues, the records available and your ability to meet deadlines. A certified public accountant, enrolled agent or tax attorney may assist within an appropriate scope of representation. Use the applicable FTB 3520 PIT or FTB 3520 BE declaration when appointing a representative. Professional assistance does not guarantee a particular result.

Conclusion: Take Control of Your FTB Audit Today

A California FTB audit is a serious matter, but it is a manageable one. You don’t have to face it alone.

FTB examinations can lead to proposed tax adjustments, interest, and applicable penalties. Respond to the notice promptly and consider representation for disputed issues.

Review the relevant notices, filing history, records, and deadlines before choosing a response. Evaluate professional assistance according to the facts, applicable law, and agreed scope of representation.

For help evaluating your notices and options, contact the firm about your California state tax matter.