In civil procedure, a party's claim is a counterclaim if the defending party has previously (in the present action) made a claim against the claiming party.
Examples of counterclaims include:
- After a bank has sued a customer for an unpaid debt, the customer counterclaims (sues back) against the bank for fraud in procuring the debt. The court will sort out the different claims in one lawsuit (unless the claims are severed).
- Two cars collide. After one person sues for damage to her car and personal injuries, the defendant counterclaims for similar property damage and personal injury claims.
Counterclaims did not exist at common law; they are an invention of modern civil procedure.
Read more about Counterclaim: Under The United States Federal Rules of Civil Procedure