In North Carolina Small Claims Court, a party is not required to file a counterclaim, even if it has one. So for example, if you are suing a company for a breach of warranty, and you still owe money on your purchase, that company does not have to counterclaim against you for the balance in a small claims action. It can wait to file a separate suit.
North Carolina General Statutes section 7A-219 provides that "failure by a defendant to file a counterclaim in a small claims action assigned to a magistrate, or failure by a defendant to appeal a judgment in a small claims action to district court, shall not bar such claims in a separate action." Those with some familiarity with the legal system might recognize this as an exception to the general rule (embodied in Rule 13(a) of the North Carolina Rules of Civil Procedure) which ordinarily requires counterclaims to be filed in the same action as the pending claim, so that the courts can resolve all issues between the parties in one action, rather than having multiple suits.
For small claims actions in North Carolina, the "compulsory counterclaim" rule does not apply.