How to Handle a Tax Audit in California
A tax audit is a review of information reported to the California Franchise Tax Board (FTB), the Internal Revenue Service (IRS), or another state agency. It does not automatically mean you have done something wrong. Often, the agency is checking a mismatch, a deduction, a credit, or information supplied by an employer or financial institution.
For Australians, California’s system may feel unfamiliar. The FTB handles many state income-tax matters, while the IRS deals with federal tax. California businesses may also receive notices from the California Department of Tax and Fee Administration (CDTFA) about sales and use tax, payroll-related records, or business activity.
Keep every notice, envelope, attachment, and deadline in one secure folder. Whether you live in Sydney, Melbourne, Brisbane, or California, digital scans can help you organise evidence while paper copies provide a reliable backup. Treat the audit as a formal administrative process rather than an informal request for explanations.
The safest response is prompt, factual, and documented. Read the notice carefully, identify the tax year and issues under review, and avoid sending unrelated documents that could create confusion.
Identify The Agency And Scope
The first step is to establish who contacted you. An FTB notice may concern California residency, income, deductions, credits, withholding, or a change made after information was received from the IRS. An IRS audit can affect your federal return without automatically deciding your California position.
Check the notice number, tax period, response deadline, and requested records. If the letter refers to a desk audit, correspondence audit, or field examination, the format and level of contact may differ. A desk audit is usually handled by mail or an online portal, while a field examination may involve a meeting at your home, business, or representative’s office.
Be alert to impersonation scams. Tax agencies generally provide written identification and secure communication methods; they should not demand gift cards, cryptocurrency, or immediate payment through an unknown link. When checking public contact details, use the agency’s official website rather than search advertisements or unsolicited messages. A government information source such as Córdoba public information can illustrate the general principle of verifying an agency through an established public domain, although it is not a California tax authority.
Protect The Response Deadline
A notice normally states when your reply must arrive, not merely when you must post it. Allow time for delivery, scanning, and possible technical problems with an online submission. If the deadline is close, contact the agency using the number printed on the notice and record the date, time, representative’s name, and instructions provided.
Requesting an extension may be possible, but never assume it is automatic. An extension to provide records usually does not extend the time to challenge an assessment or pay an amount due. Keep proof of online submissions, certified mail, courier delivery, and uploaded files.
Australians accustomed to using myGov and the Australian Taxation Office for digital tax administration should remember that California processes vary by agency. Create separate logins where required and avoid sending sensitive tax files over ordinary email unless the agency or adviser has provided a secure method.
Gather Relevant Evidence
Collect the filed return, amended returns, W-2 and 1099 forms, bank statements, invoices, receipts, mileage logs, lease documents, investment statements, and correspondence supporting the disputed items. Arrange documents by tax year and audit issue. A short index explaining what each file proves can make the response easier to review.
For residency questions, assemble travel records, lease agreements, utility bills, employment records, driver licence details, voter registration, and evidence of where your family and main financial interests were located. A person who moved between California and Australia may need to show dates of arrival, departure, work performed, and the location of their home during the relevant period.
Do not reconstruct records carelessly. If a receipt is missing, explain the situation and provide alternative evidence rather than creating an estimate that looks precise but cannot be supported.
Review Deductions And Credits
Audits often focus on deductions and credits because they reduce taxable income or tax payable. Check whether each claimed expense was allowable, connected to income production, correctly allocated between personal and business use, and supported by records made near the time of payment.
Business owners should separate private spending from business transactions. California may scrutinise vehicle use, home-office costs, contractor payments, travel, meals, depreciation, and sales-tax treatment. Australian habits such as using a personal card for mixed household and work purchases can make reconstruction difficult, so clear account separation is valuable.
Insurance and transport records may also help establish business use or property costs. For background on comparing coverage and documenting policy details, see auto insurance policies, especially if vehicle expenses appear in the return.
Decide Whether To Use A Representative
You may respond yourself, but a certified public accountant, enrolled agent, or tax attorney can help interpret technical issues and communicate with the agency. A representative is particularly useful when the audit involves several years, substantial penalties, business records, residency disputes, or possible fraud allegations.
A tax professional may use a power of attorney or information-authorisation form. Understand what authority you are granting and remain involved in major decisions. Give the adviser a complete chronology, including previous notices, phone calls, payments, and explanations already submitted.
Do not ignore an audit because professional fees seem expensive. Ask for a clear scope of work and estimate, then compare that cost with the potential tax, interest, penalties, and time involved.
Respond Clearly And Keep Control
Answer each request in the same order as the notice. Provide copies rather than irreplaceable originals, label files consistently, and include a short cover letter that explains where each requested item appears. If a document does not exist, say so directly and describe what alternative evidence is enclosed.
Avoid argumentative language, speculation, and unnecessary personal details. A concise explanation supported by records is usually stronger than a long narrative. Never alter dates, receipts, invoices, or electronic files after receiving the notice.
If the agency proposes additional tax, review the proposed assessment before paying or appealing. You may be able to dispute factual errors, provide further evidence, request an administrative review, or pursue an appeal within a strict time limit.
Compare The Main Audit Paths
The correct response depends on the agency, the subject matter, and the stage of the review. The following guide provides a practical starting point:
| Audit situation | Main records | Sensible next step |
|---|---|---|
| FTB income-tax review | State return, wage forms, residency evidence, deduction records | Reply through the stated channel before the deadline |
| IRS federal audit | Federal return, information forms, accounting records | Reconcile the federal figures and obtain advice if complex |
| CDTFA sales-tax review | Sales invoices, exemption certificates, purchase records, ledgers | Separate taxable and non-taxable transactions |
| Residency dispute | Travel history, leases, employment and family records | Build a dated timeline of where you lived and worked |
| Proposed additional assessment | Notice, calculation, payment history, supporting evidence | Check appeal rights, interest, penalties, and payment options |
Keep an audit log with dates, submissions, conversations, and outstanding items. This is useful if the matter is transferred to another officer or if you later need to prove that a response was timely.
The key point to remember is that a California tax audit should be handled as a deadline-driven evidence review: verify the agency, preserve records, answer only the issues raised, and obtain qualified advice when the amount or complexity justifies it.