A single judge can handle normal contentious and penal cases. A college of at least three judges, however, must try cases involving an excommunication, the dismissal of a cleric, or a contested marriage or ordination annulment (can. 1425 §1). The bishop can assign up to five judges to a case that is very difficult or important (can. 1425 §2). Otherwise, the judicial vicar assigns cases to the judges and, in those cases which require three or more judges, presides over the panel or assigns one of his assistant judicial vicars to preside, if there are any. The judicial vicar and the assistant judicial vicars must be priests with doctorates or at least licenses in canon law. The other judges need only be clerics with licenses, but the episcopal conference can permit properly qualified members of the laity to serve as judges on a panel.
There are other officers of the tribunal. The promoter of justice, for instance, is a canon lawyer whose job is to represent the diocese as the prosecutor in penal cases and who also can intervene in contentious cases if they concern the "public good", acting as a watch dog for the people of the diocese. Another important officer is the defender of the bond, another canon lawyer whose job is to present reasons to the tribunal why a marriage is valid in cases of alleged nullity and why an ordination is valid in the rare cases of alleged nullity of Holy Orders. The tribunal also has notaries who swear in witnesses and commit their testimony to writing. Like any good legal system, parties in a case have the right to appoint an advocate who can argue for them at the tribunal. If a person cannot afford an advocate, the tribunal can assign one to them free of charge.
Unlike courts of common law tradition, ecclesiastical tribunals do not follow the adversarial system. Based on the same Roman civil law that is behind much European law, the procedure of a canonical court is more akin to the inquisitorial system, with the judges leading the investigation. As a general rule, the defendant has the favorable presumption of law, which means that the defendant will win by default unless a majority of the judges is convinced with moral certainty of the petitioner's case (can. 1608). This presumption also applies in penal cases (can. 1728). There are few exceptions to this rule; in those cases, the burden shifts to the defendant.
Some matters cannot be introduced at the diocesan level and can only be introduced before the following:
Some cases are automatically appealed (for instance, when a marriage is found to be null). The appealing party does not need to appeal to the metropolitan; the party can instead appeal to the Holy See, in which case the Sacra Rota Romana would hear the case in the second instance. If the case was before the Rota in the first instance, then a different panel of the Rota hears it in the second instance.
With the exception of annulment cases, if the first instance and second instance tribunals agree on the result of the case, then the case becomes res judicata and there is no further appeal. If they disagree, then the case can be appealed to the Sacred Roman Rota, which serves as the tribunal of third instance. The Rota is a court of fifteen judges called auditors who take cases in panels of three and serve as the final arbiters of most cases.
There is no appeal from a case which the Pope has decided personally.
There is no right of appeal from the decision of the Apostolic Signatura (can. 1629 #1).
The other tribunal is the Apostolic Penitentiary. This tribunal has no jurisdiction in the what is known as "the external forum," meaning cases and events which are publicly known, only matters of the "internal forum," which involve entirely confidential and secret matters, including (but not limited to) what is confessed in the Sacrament of Penance. It primarily deals with cases that arise only within the confessional and which by their nature are private, confidential or whose facts are secret. Such cases are normally brought before the court by a person's confessor, who writes up the relevant facts of the cases, but only what is absolutely necessary, using standardized Latin pseudonyms. The confidentiality of the person, and the priest's absolute obligation to preserve the secrecy of the Sacrament of Penance, are still in force in such cases. This court, under the authority of the Cardinal Major Penitentiary, who acts in the Pope's name, answers the confessor and empowers him to impose a penance and lift a penalty. For instance, the act of desecrating the Eucharist is one which incurs an automatic excommunication for the person who so acts (an excommunication from the moment of the act, which no court need actually meet to impose), and the power to lift this excommunication is reserved by the Pope to himself. Should this person then approach a priest in confession, repentant, and explain his act and the fact that he acted in secret, the confessor would write to the tribunal laying out the simplest outline of facts, keeping the person's identity secret, and would most likely be empowered to lift the excommunication and impose some private act of penance on the person.
It should be noted that any act which involves the rights or victimization of another person is by definition a matter for the external forum.
Offences against ecclesiastical laws are dealt with differently based on whether the laws in question involve church doctrine. For non-doctrinal cases, the lowest level of the court is the Archdeaconry Court, which is presided over by the local Archdeacon. The next court in the hierarchy is the Bishop's Court, which is in the archdiocese of Canterbury called the Commissary Court and in other dioceses the Consistory Court. The Commissiary Court is presided over by a commissiary-general; a Consistory Court is presided over by a chancellor. The chancellor or commissiary-general must be thirty years old and either have a seven-year general qualification under the Courts and Legal Services Act 1990 s 71 or have held high judicial office.
Specialist courts in the Province of Canterbury are the Court of Faculties, the Court of Peculiars and the Court of the Vicar-General of the Province of Canterbury. In the northern province there is the Court of the Vicar-General of the Province of York.
The next court is the Archbishop's Court, which is in Canterbury called the Arches Court, and in York the Chancery Court. Each court includes five judges; one judge is common to both courts. The common judge is called the Dean of Arches in Canterbury and the Auditor in York; he or she is appointed jointly by both Archbishops with the approval of the Crown, and must either hold a ten-year High Court qualification under the Courts and Legal Services Act 1990, s 71, or have held high judicial office. Two members of each court must be clergy appointed by the Prolocutor of the Lower House of the provincial Convocation. Two further members of each court are appointed by the Chairman of the House of Laity of the General Synod; these must possess such legal qualifications as the Lord High Chancellor of Great Britain requires.
In cases involving church doctrine, ceremony or ritual, the aforementioned courts have no jurisdiction. Instead, the Court of Ecclesiastical Causes Reserved hears the case. The Court is composed of three diocesan bishops and two appellate judges; it has jurisdiction over both of the provinces of Canterbury and York. The Court, however, meets very rarely.
Appeal from the Arches Court and Chancery Court (in non-doctrinal cases) lies to the Queen-in-Council. In practice, the case is heard by the Judicial Committee of the Privy Council, which includes present and former Lords Chancellor, a number of Lords of Appeal and other high judicial officers. The Queen-in-Council does not have jurisdiction over doctrinal cases from the Court of Ecclesiastical Causes Reserved, which instead go to an ad hoc Commission of Review, composed of two diocesan Bishops and three Lords of Appeal (who are also members of the Judicial Committee).
Commissions of Convocation are appointed by the Upper House of the Convocation of Canterbury or of York to try a bishop for an offence (except for an offence of doctrine). Both Convocations make the appointment if an Archbishop is prosecuted. This would comprise four diocesan bishops and the Dean of the Arches.
Courts and procedure for trials of bishops are provided for by the Canons of the General Convention (the triennial legislative body of the national church). There is one Court for the Trial of a Bishop, composed of nine bishops (though there have been proposals to include lay persons and lower clergy in this court). Appeals are heard by the Court of Review for the Trial of a Bishop, also comprising nine bishops. The Constitution of the national Episcopal Church provides that this court must be composed only of bishops.
For priests and deacons, initial trial is held by an ecclesiastical court established by the diocese in which the cleric is canonically resident. Appeals are taken to the Court of Review for the Trial of a Priest or Deacon, one of which is established in each of the nine provinces of the Episcopal Church (a province is a geographic combination of dioceses). Dioceses have some discretion about the procedure and membership for the ecclesiastical court, but most rules and procedure is established church-wide by the national canons. Trial courts are made up of lay persons and of priests or deacons, with the clergy to have a majority by one. The various courts of review comprise one bishop, three priests or deacons, and three lay persons.
Since the 18th century the Constitution of the national Episcopal Church has permitted the creation of a national Court of Appeal, which would be "solely for the review of the determination of any Court of Review on questions of Doctrine, Faith, or Worship." No such court has ever been created, though proposals have occasionally been made to establish the House of Bishops itself as such a court, and such a system would likely be a robust exercise of the Church's right of self-governance under the First Amendment of the U.S. Constitution.