Not before a judge.
This legal maxim is of latin origin meaning a legal proceeding outside the authority of the judge, that is, without a judge, with no proper presence, or without any legal jurisdiction. Any order or sentence passed by a court or tribunal, which does not possess the authority to try an accused of that particular offence, shall be in violation of the law of the land, not enforceable, and it would be termed as Coram non judice.
Since the case belonged to the jurisdiction of B, therefore, the order passed by A is “Coram non judice”.
State of Rajasthan v. Jeev Raj (AIR 2011 12 SCC 252)
In this case the court held that, a decree passed by a court without jurisdiction over the subject-matter or on other grounds which go to the root of its exercise or jurisdiction, lack inherent jurisdiction. It is a “Coram non judice”.