Negligent Undertaking in California: The 2026 Guide

Overview

The negligent undertaking doctrine imposes liability on a person who voluntarily assumes a duty to act and then performs that undertaking negligently. Unlike most tort obligations, this duty is not imposed by law from the outset -- it arises from the defendant's own voluntary conduct. Once a person undertakes to render services for the protection of another, the law requires that the undertaking be performed with reasonable care.

This guide covers the Restatement foundations, the elements of negligent undertaking claims, Good Samaritan protections, and practical applications in California personal injury cases. It is written for injured people, their families, and the lawyers who represent them.

Key takeaway

Negligent undertaking creates liability not for failing to act in the first place, but for acting carelessly once the defendant has voluntarily chosen to act. California has adopted both Section 323 and Section 324A of the Restatement (Second) of Torts. The doctrine is particularly useful against security companies, inspection services, and contractors who assumed safety responsibilities and performed them negligently.

The Restatement Foundations

Section 323 (Direct Recipient)

Restatement (Second) of Torts Section 323 provides that a person who undertakes to render services to another -- gratuitously or for consideration -- which they should recognize as necessary for protection of the other's person or property, is liable for physical harm resulting from failure to exercise reasonable care, if the failure increases the risk of harm or the harm is suffered because of reliance upon the undertaking.

Section 324A (Third-Party Claims)

Section 324A extends the doctrine to situations where services are rendered to one person but a third party is injured. Liability attaches if the failure to exercise reasonable care increases the risk of harm, the defendant undertook a duty owed by the other to the third person, or the harm was suffered because of reliance by the other or the third person.

Section 323 vs. 324A

Section 323 governs the relationship between the person performing the service and the direct recipient. Section 324A governs liability to third parties who were not direct recipients but who were foreseeably endangered by the negligent performance.

Elements of a Negligent Undertaking Claim

Under Section 323

The plaintiff must prove: (1) the defendant undertook to render services, gratuitously or for consideration; (2) the services were necessary for protection of the plaintiff's person or property; (3) the defendant failed to exercise reasonable care; (4) the plaintiff suffered physical harm; and (5) either the failure increased the risk of harm or the plaintiff relied on the undertaking.

Under Section 324A

The third-party plaintiff must prove: (1) the defendant undertook services to another person or entity; (2) the services were necessary for protection of third persons; (3) failure to exercise reasonable care; (4) physical harm to the third party; and (5) any one of: increased risk, undertaking a duty owed by the other to the third person, or reliance by the other or the third person.

Injured because someone performed a duty carelessly? Talk to a California injury attorney now. Call (424) 353-4624 or text us. Free. Confidential. No obligation.

The Voluntary Undertaking Requirement

An undertaking can be express (a verbal or written promise), implied by conduct (beginning to perform a safety inspection), contractual (a security company agreeing to patrol), or gratuitous (a bystander who begins a rescue). The defendant's duty extends only to the scope of the undertaking actually assumed.

Increased Risk

Under both Section 323(a) and Section 324A(a), the plaintiff can establish causation by showing the defendant's negligent performance increased the risk of harm beyond what it would have been absent the undertaking. This does not require proof that the negligence was the sole cause -- only that it made harm more likely.

Element	What Plaintiff Must Show	When It Applies
Increased risk	The negligent undertaking made harm more likely than if the defendant had not acted	Defendant's negligent act worsened plaintiff's position
Reliance	Plaintiff changed position based on the defendant's assumed duty	Plaintiff was worse off because they depended on the undertaking

Reliance

Reliance means the plaintiff or the person to whom services were rendered changed their position based on the defendant's undertaking. Typically, the plaintiff forebore from taking self-protective measures, failed to seek help from others, or placed themselves in danger based on the defendant's assumed protection.

Good Samaritan Protections

California provides statutory immunity for certain good-faith emergency rescue efforts to encourage bystander intervention. Health and Safety Code Section 1799.102 provides that no person who renders emergency care in good faith, without compensation, at the scene of an emergency shall be liable for civil damages. However, this protection does not extend to gross negligence, willful misconduct, paid rescuers, or care in hospital settings.

Common Applications in PI Practice

Security Companies

Security companies that contract to provide patrol, monitoring, or guard services are frequently subject to negligent undertaking claims. When a security company assumes a duty to protect a premises and then performs that duty negligently -- guards sleeping, cameras not monitored, patrols skipped -- both reliance and increased risk may be established.

Inspection Services

Companies or individuals who undertake safety inspections may be liable when a negligent inspection fails to identify a hazard. This includes building inspectors, safety consultants, insurance company inspectors, and environmental testing firms.

Maintenance and Repair Contractors

Contractors who undertake to repair or maintain equipment, vehicles, or premises and perform the work negligently may be liable to third parties under Section 324A.

Defenses to Negligent Undertaking Claims

Common defenses include: no undertaking occurred; the injury fell outside the scope of the assumed duty; the negligent performance neither increased risk nor induced reliance; Good Samaritan immunity for emergency rescue situations; and the plaintiff's own comparative fault.

Think someone's carelessness made your situation worse? We handle negligent undertaking cases throughout California. Call (424) 353-4624 or text us for a free case review.

Cross-References

Independent Contractors — contractor undertakings and hirer liability
Assumption of Risk — firefighter's rule and professional rescuer doctrine
Premises Liability — security company undertakings on premises
Pure Comparative Fault — plaintiff's comparative negligence
Non-Economic Damages — pain and suffering from negligent undertaking
Proving Damages — evidence strategies for undertaking claims

Common Questions

What is the difference between negligent undertaking and ordinary negligence?

In ordinary negligence, the law imposes a duty on the defendant. In negligent undertaking, the defendant had no pre-existing duty but voluntarily chose to act, creating a duty to perform with reasonable care. The doctrine is particularly useful against defendants who would otherwise have no legal obligation to the plaintiff.

Can I sue a security company that failed to protect me?

Potentially yes. Security companies that contract to provide patrol or monitoring services are frequently subject to negligent undertaking claims under Restatement section 324A. If the company assumed a duty to protect the premises and then performed that duty negligently -- for example, guards not patrolling or cameras not monitored -- you may have a viable claim.

Does the Good Samaritan law protect someone who tries to help me but makes things worse?

California's Good Samaritan statute (Health and Safety Code 1799.102) protects voluntary rescuers from liability for ordinary negligence during emergency care. However, this protection does not extend to gross negligence, willful misconduct, or paid rescuers. The line between ordinary and gross negligence is intensely fact-specific.

What does increased risk mean in a negligent undertaking case?

Increased risk means the defendant's negligent performance made the harm more likely than if the defendant had never acted at all. For example, a safety inspector who conducts a negligent inspection and misses a hazard increases the risk because the hazard continues undetected. The plaintiff does not need to prove the defendant was the sole cause -- only that the negligence made harm more likely.

Sources & Citations

Our offices

Tarzana 18653 Ventura Blvd., Suite 361 Tarzana, CA 91356 Open in Maps →

Los Angeles 5411 S. Broadway, Suite 201 Los Angeles, CA 90036 Open in Maps →

Local Resources

Cedars-Sinai EmergencyLos Angeles trauma center for serious injuries.
Providence Tarzana Medical CenterSan Fernando Valley emergency care, 24/7.
LA Superior Court · Stanley MoskCivil filings for LA County cases.
CA Bureau of Security & Investigative ServicesVerify security company and guard licensing.
CA State Bar LookupVerify any attorney's license before hiring.

Restatement (Second) of Torts § 323. Negligent performance of undertaking to render services for protection of another.
Restatement (Second) of Torts § 324A. Liability to third persons for negligent performance of undertaking.
California Health & Safety Code § 1799.102. Good Samaritan immunity for emergency care rendered in good faith without compensation.
CACI 460 — Negligent Undertaking. Jury instruction for voluntarily assumed duty claims.
CACI 461 — Negligent Undertaking: Third-Party Claim. Jury instruction for Section 324A third-party claims.
California Civil Code § 1714.21. Immunity for use of automated external defibrillator in emergency.

Negligent Undertaking in California.