How cases are heard
The practice and procedure of the High Court in all civil proceedings is regulated by the High Court Rules 2016. The Rules set out how proceedings are started and specify the documents that must be filed, the content of those documents and how they are to be served. The Rules also provide detailed guidance on pre-trial matters such as case management, interim relief, discovery and inspections. The case management procedure aims to ensure that cases are processed through the system efficiently.
The High Court has unlimited jurisdiction. However, cases come to the Court when the relief sought exceeds $350,000, the limit of the District Court’s jurisdiction. Cases also come before the High Court where lower courts lack jurisdiction to deal with certain matters, such as judicial review and admiralty.
The Judicial Review Procedure Act 2016 provides a single procedure for the judicial review of the use or non-use of statutory powers. The purpose of the Act is to simplify the procedure for bringing judicial review that had been developed under the common law. Part 30 of the High Court Rules provides guidance on the commencement of judicial review applications.
Cases can also come to the High Court by way of an appeal from a lower court, such as the District Court, Family Court or the Environment Court. Appeals are generally conducted through a rehearing. That means the High Court judge can come to a different decision to the lower courts on the evidence presented and on the law.
The High Court can order the removal of civil proceedings from the District Court to the High Court, and the High Court can order a civil proceeding to be transferred to the Court of Appeal in exceptional circumstances. This power was exercised in New Zealand Māori Council v Attorney-General in light of significant public interest in the case, urgency and the likelihood of an appeal regardless of the outcome. 
The High Court usually has its powers exercised by one judge. There is provision for the High Court to sit as a full court, which is defined as two or more judges sitting constituting the court. The full court is reserved for cases of particular significance or in cases where a statute requires a specific number of judges. There is now only one such statute. Under s 235 of the Electoral Act 1993, trial of election petitions must take place before three judges. Apart from that circumstance, it is at the discretion of a judge to determine whether or not to constitute a full court. A number of considerations are pertinent, including administrative considerations, the potential difficulties of two judges disagreeing and the desirability of applying two or more judicial minds to find-finding. A full court was considered appropriate in the case that challenged the Commission of Inquiry into Certain Matters Relating to Taxation (the Winebox inquiry). Public interest and the status of the Commissioner as a former Chief Justice made the case exceptional.  In the past, full courts have also convened in cases that involved applications under s 88B of the Judicature Act 1908 to restrain a vexatious litigant from bringing further proceedings. 
A complex commercial case may be heard by a specialist judge drawn from the commercial panel. The commercial panel was established by s 19 of the Senior Courts Act 2016 and commenced on 1 September 2017.
Commercial cases are defined in cl 5 of the Senior Courts (High Court Commercial Panel) Order 2017. They cover high-value disputes (over $2 million), complex and difficult matters of commercial law as well as proceedings brought by public authorities to enforce regulatory standards of commercial behaviour.
Either the plaintiff or defendant may nominate a case to be heard by a panel judge. The Chief High Court Judge considers these applications and, if they meet the criteria in the Commercial Panel Order, she will assign a judge from the panel to hear the case.
The judges currently assigned to the commercial panel are Justices Thomas, Venning, France, Lang, Mallon, Wylie, Ellis, Peters, Katz, Muir, Fitzgerald, Jagose and Osborne. Their appointments are for three years. These judges will continue to carry out the full range of High Court work (other civil work, criminal work and appeals).
As a general rule, the panel judge will case manage the case and hear any interlocutory matters. Commercial cases will generally be heard in the registry in which they were filed.
Lay members may be appointed to assist Judges of the High Court under three pieces of legislation:
From time to time additional members may be appointed, and members may have their terms renewed subject to the relevant legislation.
The Court selects lay members from a “pool” of experts. Once a lay member has been appointed to a case, the lay member becomes a member of the Court for the purposes of that case.
Appointments under legislation
Commerce Act 1986
Under ss 77 and 78 of the Commerce Act, a least one lay member is appointed to the Court when the Court exercises its appellate jurisdiction in respect of Commerce Commission determinations. Lay members have knowledge in, or are experienced in, industry, commerce, economics, law or accountancy.
However, under s 78, the Court may on its own motion or on application of one of the parties, appoint lay members to hear and assist the Court in relation to particular cases:
- proceedings for the recovery of pecuniary penalties for contraventions of the provisions relating to restrictive trade practices or prohibited business acquisitions under the Act;
- applications by the Commerce Commission for injunctions against such contraventions;
- actions for damages for such contraventions; and
- proceedings for the divestiture of assets or shares in respect of prohibited business acquisitions.
Lay members play a key role in ensuring that the expert evidence on complex issues is properly understood, tested and assessed by the High Court.
Human Rights Act 1993
Section 126 of the Human Rights Act 1993 allows for a panel of two lay members to be appointed to the High Court for particular cases:
- when the Human Rights Review Tribunal refers the granting of a remedy to the High Court for determination; and
- when an appeal is lodged against a decision of the Tribunal in which a question of fact is involved.
Two lay members must be appointed under s 126. However, the presence of a Judge and at least one lay member is sufficient to constitute a sitting of the Court.
The chair of the Human Rights Review Tribunal is not a panel member.
Current pool of lay members Human Rights Review Tribunal (PDF, 116 KB)
Land Valuation Proceedings Act 1948
Section 3 of the Land Valuation Proceedings Act 1948 provides for the Governor-General to appoint two lay members of the High Court to assist the Court in hearing appeals from the Land Valuation Tribunal under a range of acts including the Rating Valuations Act 1998, the Public Works Act 1981, the Māori Reserved Land Amendment Acts 1997 and 1998. Appointments are made for a term of five years and may be renewed.
The purpose of having a registered valuer as part of the Court to hear the appeal is to add an expert valuation perspective to the assessing of evidence before the Court and to assist the judge in reaching a fair decision according to law. Under s 13 of the Act, a judge of the High Court and at least one additional member is necessary to constitute a sitting of the Court. It is usual to have one appointee who specialises in urban land valuation and one who specialises in rural land valuation.
Certain offences, because of their seriousness, can only be tried in the High Court. These offences are termed category 4 offences and include for instance murder, manslaughter and treason. Other serious offences heard in the High Court are called protocol offences.  They can be heard either in the High Court or the District Court and include offences such as serious sexual and violent offending and drug offending.
Category 4 cases are generally heard by a judge and jury. A defendant who is charged with a category 3 offence may elect to be tried by a jury or by a judge alone.
The High Court’s criminal jurisdiction includes the sentencing of a convicted person. It sentences those who plead guilty or are found guilty by trial in the High Court. It also sentences convicted persons when the District Court is obliged to transfer the proceeding to the High Court for sentencing. This happens when there has been an early guilty pleas to a category 4 offence or if a sentence of life imprisonment or preventive detention might be imposed. 
The High Court also hears appeals from judge-alone trials in the District Court. Convictions, sentences and certain pre-trial decisions may be appealed to the High Court. With regards to bail, District Court decisions granting or refusing bail can be appealed to the High Court. Where the High Court is seized of the relevant criminal proceeding, bail applications are made directly to the High Court.
 New Zealand Māori Council v Attorney-General  1 NZLR 641 (HC).
 Fay Richwhite & Co Ltd v Sir Ronald Davison (1997) 11 PRNZ 190 (HC).
 See for example Attorney-General v Siemer  NZHC 859.