A third-party complaint is a pleading used by a defendant to bring another party into a lawsuit for related liability.
It is commonly associated with claims that the third party may owe indemnity, contribution, or responsibility for all or part of the plaintiff’s claim.
Why a third-party complaint matters
Some disputes involve more than the original plaintiff and defendant. A third-party complaint can allow related liability issues to be handled in the same case instead of in separate litigation.
The court may still control whether the third-party claim is proper and whether it would complicate or delay the case.
Where a third-party complaint appears
Third-party complaints appear in civil litigation, construction disputes, insurance disputes, product cases, contract disputes, and negligence cases involving multiple responsible actors.
They are usually governed by procedural rules and court deadlines.
How it differs from nearby terms
A complaint starts the lawsuit by stating the plaintiff’s claims. A third-party complaint is filed by an existing defendant against a new party.
Joinder is the broader procedural idea of adding claims or parties.
Practical example
A property owner is sued for injuries on a construction site. The owner files a third-party complaint against the contractor, arguing the contractor must indemnify the owner if the plaintiff wins.
Related Terms
Quick check
Question: Who usually files a third-party complaint?
Answer: An existing defendant who seeks to bring a related third party into the case.