Duty to Defend
The duty to defend is a liability insurer's obligation to provide and pay for a legal defense when a suit alleges facts that potentially fall within coverage. It is generally broader than the duty to indemnify. See the full explainer.
Last updated October 13, 2026
How the duty to defend works
Many liability policies say the insurer has the right and duty to defend the insured against a suit seeking covered damages. In most states, courts decide whether that duty exists by comparing the allegations in the complaint with the policy language, an approach often called the "eight corners" rule. If the complaint alleges even one claim that could potentially be covered, the insurer generally must defend.
The duty is intentionally broad. It depends on what is alleged, not on whether the allegations are true, and it is triggered by potential coverage, not certain coverage. Where the duty applies, many courts require the insurer to defend the whole suit even if only some claims could be covered. The duty to indemnify, meaning the obligation to pay a settlement or judgment, is decided later, based on the facts actually established.
Jurisdictions differ. Some allow extra facts outside the complaint to be considered, and a few recognize that unpleaded facts can trigger a defense. Whether defense costs erode limits also depends on the policy. See defense costs.
Example
A customer sues a software company alleging both negligent performance of services and intentional misrepresentation. The policy covers negligence but excludes intentional acts. Because at least one allegation is potentially covered, the insurer may need to defend the suit, possibly under a reservation of rights, even though it may never have to pay a judgment on the excluded claim.
What to watch for
- Not every policy has this duty. Many D&O and professional liability policies instead reimburse defense costs, or let the insured choose counsel with insurer consent. Read the wording.
- Prompt notice. Late tender of a claim can jeopardize the defense obligation. Notify the insurer as soon as a suit or claim arrives.
- Choice of counsel. The insurer often selects defense counsel, and a reservation of rights can change who controls the defense in some states.
- Defense inside limits. Some policies count defense spending against the limit of liability, which reduces the money left for settlements.
Duty to defend vs. related terms
- Duty to defend vs. duty to indemnify. The duty to defend is about providing a defense and is judged mainly on the allegations. The duty to indemnify is about paying a judgment or settlement and depends on the facts established.
- Duty to defend vs. duty to reimburse. Under some policies, the insurer has no duty to defend. It agrees instead to advance or reimburse defense costs that the insured incurs, often with the insurer's consent to counsel and rates. Many D&O and professional liability policies work this way.
- Duty to defend vs. reservation of rights. A reservation of rights is the insurer's notice that it is defending while it reserves the right to dispute coverage later.
- Duty to defend vs. defense costs. The duty is the obligation. The defense costs are the money spent. Whether they reduce the limit depends on the policy.
- Duty to defend vs. right to select counsel. Who picks the lawyer is a separate question. Some states require insurers to pay for independent counsel in certain conflict situations, and the rules vary.
Second example: no potentially covered allegation
A hypothetical company is sued by a customer who alleges only that the company breached a services contract by refusing to refund fees. The company's policy covers damages from negligent acts but has an exclusion for liability that exists only because of a contract. If every allegation falls within a clear exclusion, the insurer may decline to defend. Declining carries risk for the insurer if a court later finds that at least one allegation was potentially covered, since insurers that wrongly refuse a defense can face consequences that go beyond the cost of the defense. For the company, the key points are to tender the claim anyway, request the insurer's position in writing and talk to coverage counsel if the insurer refuses.
What to do when you receive a claim or lawsuit
This is general information, not legal advice. Practical steps often include:
- Send notice quickly. Provide the complaint, demand letter or subpoena and any related papers to the insurer, and to your broker, as soon as they arrive.
- Tender to every policy that might apply. One lawsuit can implicate general liability, E&O, D&O, cyber and other coverage. Notify each potentially responsive insurer.
- Watch the deadlines. The insurer's decision does not stop the court's calendar, so respond to deadlines for answers and other filings.
- Do not settle or admit liability on your own. Most policies require the insurer's consent first.
- Ask for the coverage position in writing. Find out whether the insurer will defend, whether it reserves rights and who will control the defense.
- Keep records. Save communications and invoices, which matter for defense cost reimbursement and any later dispute.
Why it matters for technology, AI, fintech and digital-asset companies
These companies often face novel claims, such as AI output disputes or token-related allegations, where it is unclear whether the complaint fits standard coverage grants. Whether a policy carries a duty to defend or reimburses costs changes how litigation is funded early on, when it matters most.
The same facts can trigger several policies at once, such as a customer suit that alleges a product failure, a privacy breach and a misstatement about capability. Because the duty to defend turns on the complaint, how the plaintiff pleads the case can decide which policy responds. See general liability, errors and omissions and AI liability for how these policies address defense, and commercial general liability and professional liability for the differences in wording.
Related terms
Frequently asked questions
What is the duty to defend?
The duty to defend is a liability insurer's obligation to provide and pay for a legal defense when a suit alleges facts that potentially fall within coverage. It is generally broader than the duty to indemnify, and it depends on the policy wording and the jurisdiction.
What is the eight corners rule?
It is a test many courts use to decide whether an insurer must defend. The court compares the four corners of the complaint with the four corners of the policy. If the complaint alleges facts that could be covered, the duty to defend generally applies.
What is the difference between the duty to defend and the duty to indemnify?
The duty to defend concerns paying for the legal defense and is triggered by potentially covered allegations. The duty to indemnify concerns paying a judgment or settlement and depends on the facts actually established. An insurer can owe a defense yet ultimately owe no indemnity.
Can an insurer refuse to defend a lawsuit?
Yes, if it concludes that no allegation is potentially covered, though that is a risky position if a court later disagrees. An insurer may also defend under a reservation of rights while it reviews coverage. If an insurer declines to defend, consider talking to coverage counsel promptly.
When does the duty to defend end?
Commonly when the suit is resolved, when the policy limit is used up by payments, or, in some jurisdictions, when a court determines there is no coverage. Some policies define the end point in their own terms. Check the policy and the rules in your state.
What should I do first when my company is sued?
Send the complaint and related papers to your broker and insurer immediately, notify each policy that might apply, watch court deadlines and avoid admitting liability or settling without the insurer's consent. Involve your own counsel as appropriate. This is general information, not legal advice.
Do D&O and professional liability policies have a duty to defend?
Many do not. They more often use a duty to advance or reimburse defense costs and let the insured choose counsel with the insurer's consent. Some professional liability forms do include a duty to defend. The policy wording controls, so confirm which approach applies.
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