The Work Product Doctrine in California: Are a Consultant's Report and Investigation Notes Protected?
Last updated: November 2026. Reviewed by Pavel Kolmogorov, California business litigation attorney (State Bar No. 321018).
The work product doctrine is the California rule that protects an attorney's case preparation from discovery. A writing that reflects an attorney's impressions, conclusions, opinions, or legal research or theories is never discoverable. Other work product is discoverable only if withholding it would unfairly prejudice the other side or cause an injustice. (Code Civ. Proc., § 2018.030.) A consultant's report prepared at the attorney's request to help prepare the case has at least that second, conditional protection. Kolmogorov Law, P.C. represents companies and their owners in business disputes.
Call (909) 235-6116 or contact us online to discuss a demand for investigation files, notes, or consultant reports.
The two levels of protection
The statute states its purpose. It preserves the right of attorneys to prepare cases with the privacy needed to investigate the unfavorable aspects as well as the favorable ones. It also prevents attorneys from taking undue advantage of an adversary's industry and efforts. (Code Civ. Proc., § 2018.020.)
Protection comes in two strengths. The first is absolute: a writing that reflects an attorney's impressions, conclusions, opinions, or legal research or theories is not discoverable under any circumstances. The second is qualified. Other work product is not discoverable unless the court determines that denying discovery will unfairly prejudice the party seeking it in preparing its claim or defense, or will result in an injustice. (Code Civ. Proc., § 2018.030, subds. (a), (b).)
How it differs from attorney-client privilege
The privilege covers confidential communications between lawyer and client, and our page on attorney-client privilege explains it. Work product covers what the lawyer, or someone acting at the lawyer's direction, creates in preparing the case, even if the client never sees it. California courts treat the attorney, not the client, as the holder of work product protection.
Neither one hides facts. A company must still answer truthfully about what happened, even when its lawyer's notes about those events are protected.
Witness statements and internal investigations
After an incident, a company may interview the people involved. Whether those interviews can be obtained turns on who directed them. The California Supreme Court held that witness statements obtained through an interview conducted by an attorney, or by an attorney's agent at the attorney's behest, are work product. They receive at least qualified protection as a matter of law. They receive absolute protection where the attorney shows that disclosure would reveal the attorney's impressions, conclusions, opinions, or theories, which the trial court may test by private review of the material. (Coito v. Superior Court (2012) 54 Cal.4th 480.)
The party seeking a qualified item carries the burden of showing unfair prejudice or injustice. The court gave the example of a witness who is no longer available. (Coito, supra, 54 Cal.4th 480.) An investigation that managers run on their own, for business reasons, stands on different footing, because no attorney directed it.
The consultant's report
A Court of Appeal has summarized the rules for consultants. A consulting expert's report, prepared at the attorney's request and for the purpose of helping the attorney prepare for trial, is work product. It has conditional protection and cannot be discovered without good cause. Any part that reflects the attorney's own impressions or theories has absolute protection. The protection changes when the expert becomes a trial witness. Once it is reasonably certain the expert will testify, the report becomes discoverable, because the expected testimony generally establishes good cause. If one report mixes advice to the attorney with the opinions the expert will give at trial, the advisory portion keeps its conditional protection. (DeLuca v. State Fish Co. (2013) 217 Cal.App.4th 671.)
So ask three questions about the report. Who hired the consultant, the company or its lawyer? Why was the report written: to prepare for a dispute, or to fix an operational problem, satisfy a customer, or support an insurance claim? Will the consultant testify? Our page on expert witness disclosure explains when a testifying expert's reports must be exchanged.
The privilege log
A response objecting to a document demand must identify with particularity what is being withheld and state the specific ground. If the ground is work product, that claim must be expressly asserted. The response must also give enough factual information for the other parties to evaluate the claim, including, if necessary, a privilege log. (Code Civ. Proc., § 2031.240, subds. (b), (c).)
A log ordinarily lists each withheld document with its date, its author and recipients, a short description, and the protection claimed. California appellate courts have held that a late or inadequate log does not by itself waive objections that were timely asserted. The remedy is an order for a proper log, with monetary sanctions where warranted.
Missing the response deadline is different. A party that fails to serve a timely response to a document demand waives its objections, including work product, unless the court grants relief. (Code Civ. Proc., § 2031.300, subd. (a).)
Protected material produced by mistake
An electronic production may include a protected file by mistake. If electronically stored information produced in discovery is subject to a claim of privilege or work product, the producing party may notify the recipient of the claim and its basis. The recipient must immediately sequester the material and either return it or present it to the court under seal. It may not use or disclose the material until the claim is resolved. A recipient that disputes the claim may bring a motion within 30 days of receiving it. (Code Civ. Proc., § 2031.285.)
If your business wants the other side's materials
Work product claims can be tested. A log that gives no dates, authors, or descriptions can be challenged by a motion to compel a further response. A document created in the ordinary course of business, before any lawyer was involved, falls outside the descriptions of work product in the decisions above. For qualified work product, the showing is unfair prejudice or injustice, for example that the witness can no longer be found. And a report generally becomes discoverable once it is reasonably certain its author will testify.
What to bring to the first meeting
- The discovery demand or subpoena and any response or privilege log served so far.
- The report, notes, or investigation file at issue, without circulating it further.
- The engagement letter or email showing who retained the consultant and when.
- A timeline of the incident, the first notice of a claim, and the lawyer's involvement.
Frequently asked questions
The other side wants the report our consultant wrote after the incident. Is it protected?
It depends on why the report was written and for whom. In California, a consulting expert's report prepared at an attorney's request to help prepare the case is work product and cannot be obtained without good cause. A report written for ordinary business reasons, with no lawyer directing it, does not fit that description. The protection also changes if the consultant is later named as a testifying expert.
What is the work product doctrine in California?
It is the protection in Code of Civil Procedure section 2018.030 for an attorney's case preparation. Writings that reflect the attorney's impressions, conclusions, opinions, or legal research or theories are never discoverable. Other work product can be obtained only if the court finds that withholding it would unfairly prejudice the party seeking it or would result in an injustice.
What is a privilege log?
A privilege log is a list of the documents a party is withholding from production on a claim of privilege or work product. California Code of Civil Procedure section 2031.240 requires a response to give enough factual information for the other side to evaluate the claim, including a log if necessary. Each entry ordinarily gives the date, the author and recipients, and the protection claimed.
Our privilege log was late and incomplete. Did we waive the privilege for those documents?
Not necessarily. California appellate courts have held that when privilege and work product objections were timely asserted in the response, a trial court may not treat them as waived because the log was missing, late, or inadequate. The court can order a proper log and impose monetary sanctions. If no timely response was served at all, the objections are waived by statute unless the court grants relief.
Who can waive work product protection?
The attorney. California courts treat the attorney, not the client, as the holder of work product protection, which is one way it differs from the attorney-client privilege held by the client. Protection can also be lost through use. Once it is reasonably certain that a consultant will testify at trial, the consultant's opinions on that subject generally become discoverable.
Talk to a California civil litigation attorney
If the other side is demanding your investigation file, or is withholding documents your case needs, call (909) 235-6116 or contact us online. Kolmogorov Law, P.C. is a business litigation firm in Irvine, California.
Related reading: our civil litigation practice and the discovery toolkit.
This page provides general information about California law and is not legal advice. Outcomes depend on the document, who created it and why, and the court.