Can a Former Employee Take My Customer List and Compete With Me in California?

Under Civil Code section 3426.1, a trade secret includes information—including a compilation—that (1) derives actual or potential independent economic value from not being generally known to others who could obtain economic value from its disclosure or use, and (2) is subject to reasonable efforts under the circumstances to maintain its secrecy.

A customer list is therefore not automatically a trade secret simply because a company calls it confidential. The content of the information and the way the business protected it matter.

In Morlife, Inc. v. Perry (1997) 56 Cal.App.4th 1514, a specialized commercial roofing company’s customer information included contact persons, pricing information, and knowledge of customers’ particular roofing needs. The company had developed it over time and restricted access through computer controls, confidentiality provisions, and an employee handbook. The Court of Appeal upheld the finding that the information qualified as a trade secret.

Morlife also illustrates the opposite principle: information readily ascertainable from public directories, websites, or ordinary market research presents a much weaker claim. The value often lies not in a customer’s name but in the nonpublic compilation surrounding it, such as:

No. Trade-secret law focuses on the protected information and whether it was improperly acquired, disclosed, or used—not the format in which it existed. Morlife indicates that protection is not necessarily lost merely because an employee remembers information rather than carrying away a printed list.

But an employer does not own an employee’s general skills, experience, or knowledge of publicly available information. The business still must establish that particular information qualifies as a trade secret and that actionable misappropriation—improper acquisition, or specified unauthorized disclosure or use under section 3426.1—occurred.

Not necessarily. The statute requires reasonable efforts under the circumstances to maintain secrecy, not a signed nondisclosure agreement. An NDA can be important evidence of those efforts, but it is neither required nor, by itself, proof of trade-secret status. Other evidence can include restricted CRM access and permissions, confidentiality policies, export restrictions, employee training, audit logs, and departure procedures for returning company information.

Sometimes—but the legal theory matters. Business and Professions Code section 16600 broadly restricts post-employment restraints on lawful competition, and section 16600.5 reinforces that policy for contracts void under section 16600.

In The Retirement Group v. Galante (2009) 176 Cal.App.4th 1226, the Court of Appeal recognized that courts may restrain actual trade-secret misuse, but rejected a broader injunction against customer solicitation that swept beyond what was necessary to protect trade secrets. Similarly, AMN Healthcare, Inc. v. Aya Healthcare Services, Inc. (2018) 28 Cal.App.5th 923 applied California’s employee-mobility policy to an employee nonsolicitation restriction.

Confidentiality agreements remain meaningful when they protect genuine confidential information rather than broadly preventing lawful competition. The real question is whether the former employee is competing lawfully or using protected information to obtain an unfair advantage.

Potentially. Civil Code section 3426.2 authorizes injunctions against actual or threatened misappropriation. But in Whyte v. Schlage Lock Co. (2002) 101 Cal.App.4th 1443, the Court of Appeal rejected the inevitable-disclosure doctrine as inconsistent with California’s policy favoring employee mobility. Joining a competitor while knowing confidential information does not, by itself, prove threatened misappropriation; emergency relief should rest on evidence of actual or genuinely threatened misuse.

Preserve relevant evidence before confrontation changes the record. Depending on the company’s systems, that may include:

Code of Civil Procedure section 2019.210 requires a party alleging misappropriation to identify the trade secret with reasonable particularity before commencing discovery relating to it. A vague claim that a former employee “knows everything about the business” differs sharply from identifying a defined confidential customer compilation or pricing methodology.

If misappropriation is proven, Civil Code section 3426.3 permits recovery of actual loss and unjust enrichment not already counted, or a reasonable royalty in appropriate circumstances. For willful and malicious misappropriation, a court may award exemplary damages of up to twice that award. Section 3426.4 permits a court to award attorney fees in specified circumstances, including willful and malicious misappropriation or claims made in bad faith—see our discussion of why winning a California lawsuit does not automatically mean recovering attorney fees.

These remedies are not automatic, and the fee provision can cut both ways: an unsupported claim brought to punish lawful competition can create risk for the plaintiff.

Civil Code section 3426.6 generally requires suit within three years after the misappropriation is discovered or reasonably should have been discovered; a continuing misappropriation is treated as a single claim. Delay is still risky—logs roll over and injunctive relief loses practical value.

The federal Defend Trade Secrets Act, 18 U.S.C. § 1836, provides a civil action for trade secrets related to products or services in interstate or foreign commerce, but also restricts injunctions that would prevent a person from entering an employment relationship.

California generally permits former employees to compete, but it does not permit them to misappropriate information that satisfies the legal definition of a trade secret. The stronger case asks what specific information was confidential, why it had value because competitors did not know it, what the business did to protect it, and what evidence shows improper acquisition, disclosure, or use.

Mahrouyan Law, P.C. represents California businesses and founders in selected trade-secret and intellectual-property disputes and business disputes involving customer relationships and competition.