A subpoena is an order directing a person to appear and to testify at a given time and place. A subpoena duces tecum requires you to bring certain documents and things with you. Subpoenas may be issued by a court, by a lawyer representing a party in a civil or criminal case, or by a government agency.

All subpoenas have the authority of either the courts or statutory law behind them and carry the threat of punishment, both fines and imprisonment, for non-compliance. (The archaic phrase appearing at the bottom of some subpoenas - "Herein fail not at your peril" - remains true today.)

Nevertheless, compliance with a subpoena may not be required, upon a formal showing to a court (referred to as a motion to "quash" the subpoena) that its terms are unreasonable or oppressive. Note, however, that this is a formal proceeding, and until such formal steps are taken by your attorneys, compliance is technically required.