The Ministry of Justice estimates courts will be able to hold 12,500 hearings over the next month.
Courthouses are continuing to operate as an essential service at a limited level using remote technology during the lockdown.
District and Youth Courts typically hear about 72,000 hearings a month, but Covid-19 protocols mean just 12,500 will be able to go ahead over the next month.
The Chief Justice and heads of court benches have met to identify what court proceedings will be given priority and how they will be heard.
These include proceedings that affect liberty of the individual, personal safety and well-being, and matters in which resolution is time-critical.
The Supreme Court, Court of Appeal, Employment Court, Environment Court, Māori Land Court, Waitangi Tribunal and Coroners Court were shut earlier this week.
Since then, courthouses that remain open have excluded anyone who is not required for court business in an effort to tighten safety measures under Covid-19 alert level 4.
Under the Criminal Procedure act, a court may exclude members of the public when necessary to avoid endangering the safety of any person present, avoid undue disruptions, or avoid prejudicing the maintenance of the law.
In a statement, Chief Justice Helen Winkelmann said the current state of emergency meant it had been necessary for the courts to exercise this power and exclude supporters.
Defendants, prosecutors, lawyers, officers of the court and accredited media are permitted to enter courts, but may be required to show identification.
Any supporter will be denied entry to a courthouse unless they get advanced permission from the judge which can be requested by phoning the Ministry of Justice on 0800 COURTS (0800 268 787).
- If you have symptoms of the coronavirus, call the NZ Covid-19 Healthline on 0800 358 5453 (+64 9 358 5453 for international SIMs) or call your GP - don't show up at a medical centre
The Secretary for Justice Andrew Kibblewhite has asked all court participants to comply with the new protocols as the country observes the nationwide lockdown.
"These steps from the Chief Justice have been taken to protect the safety of those who need to be in court for priority justice services during Alert Level 4 and to give effect to this alert level," Kibblewhite said.
Priority proceedings are listed on the Courts of New Zealand website and the District Courts website.
All counter services in courts are closed and filing of court papers is now being done electronically or via post with fees waived under the Epidemic Preparedness Act.
Justice of the Peace services have also been suspended and bailiffs will only serve urgent documents if all other options are unavailable.
Anyone unsure if they are required at court should visit the courts website or call 0800 COURTS.