Background information on the NHI

What is the NHI?

New Zealand health professionals have been using a form of the National Health Index (NHI) number for more than 30 years. It is used in hospitals, by family doctors, pharmacies, laboratories and by midwives. Most people now receive their own unique NHI number at birth. About 95 percent of New Zealand citizens have their own unique NHI number.


The NHI is not your health record, it is simply a unique combination of letters and numbers which helps identify who you are. This number is used by authorised health workers to help identify you so that you don’t have to keep repeating the same information over and over again. It can also speak for you when you cannot.


The NHI number is a unique number that is assigned to each person using health and disability support services. The NHI is an index of information associated with that unique number. The Health Information Privacy Code 2020 places restrictions on the creation and use of unique identifiers such as the NHI number.


The NHI holds the following information:

  • name (including alternative names such as maiden names)
  • NHI number
  • address
  • date of birth
  • gender
  • New Zealand resident and citizenship status (this is dependant on what application or service is used to access the NHI)
  • place of birth
  • ethnicity
  • date of death (if appropriate)


  • The name recorded on the NHI is your preferred name.  If you have previously been known to health care providers by a different name, these are held on the NHI alternative names. Having all your names ensures providers do not issue multiple NHI numbers for you.


  • It is important to keep address data up to date to ensure you get access to all the services you need. It is used for screening programme invitations and hospital appointment letters etc.


  • Gender and ethnicity are self-identified and you may want to change them.  We want the NHI to reflect how you identify yourself.

Clinical information is not recorded on the NHI.


These identifiers allow individual patients to be positively and uniquely identified for the purposes of treatment and care, and for maintaining medical records. It means that healthcare providers can be sure that they are talking about the same person, thereby reducing the chance of making a clinical decision based on wrong or incomplete information. This certainty is increasingly important as patients become more mobile, when care occurs in both the primary and secondary sectors, and where emphasis is on ‘shared’ care.


The National Health Index and the NHI number are central to the vision of safe and secure sharing of information among health providers. An NHI number is fundamental for services to link information and gain a better understanding of each person’s needs.


The complexity of hospital care and the wide variety of primary care providers has led to the development of independent clinical information systems, such as pharmacy, laboratory, and admission/discharge/transfer. Important information relating to an individual patient is often held in more than one place. The NHI number allows all this information to be brought together.

Do I have an NHI number?

About 95 percent of New Zealanders have their own unique NHI number. Health providers need the NHI number, and will assign one to you if you do not already have one. This is permitted under the Health Information Privacy Code 2020. Under this Code, health providers must tell you if they are collecting information and if they will be using it to register you on the NHI or update information already associated with your NHI number.

Where can I find my NHI number?

There are several ways to find your NHI number, including on:

  • a prescription or prescription receipt
  • a prescription medicine bottle label
  • a hospital letter
  • an x-ray or test result
  • by checking your profile on the online patient portal provided by your general practice.

If you can't find your NHI, your general practice or pharmacist may be able to assist. Don’t worry if you’re not enrolled with a GP. Your NHI will be found or assigned when you next use health and disability support services in New Zealand.

How did I get my NHI number?

Since almost 95 percent of New Zealanders have a unique NHI number, the majority of new numbers are given to newborn babies. If for some reason a person does not have an NHI number and needs medical attention, an NHI number will be assigned.

What does an NHI number look like?

An NHI number is actually a string of seven characters — the first three are letters and the last four are numbers. These characters are assigned randomly. An example of an NHI number is ABC1234. If you have been in hospital you may have seen an NHI number on your clinical notes or on the hospital identity bracelet. You may also have noticed it on a prescription or laboratory test request.

What is the NHI used for?

The NHI number is used by authorised users to:

  • obtain information from the internal systems of a hospital or provider by allowing online access to information such as diagnostic results, previous clinical events, or planned future events such as elective surgical bookings
  • access information from the Medical Warning System (MWS), such as medical warnings, medical alerts, and previous secondary care events
  • access information from the National Immunisation Register, such as immunisation status
  • record your choice of providers in the National Enrolment Service.

Is there any additional cost to the end user of the NHI?

No, there is no cost to the end users of the NHI.

Are there any links to debt collection agencies?

No, there are no links to, or associations with, debt collection agencies.


What are the benefits of having an NHI number?

For you to get the best care and support, your health professional must have the right information about you at the right time. Your NHI number identifies you and makes sure you are correctly matched with your health record. Other people may have a similar name to you, your name can be spelled wrong, or you may have changed your name by deed poll or by marriage. Having a unique number helps health workers avoid confusion.

Management of data held on the National Health Index

Who looks after the National Health Index?

The Ministry of Health acts as the custodian and has stewardship and maintenance responsibility over the National Health Index (NHI) and Medical Warning System (MWS). The Ministry of Health aims to make accurate information readily available and accessible in a timely manner throughout the health sector to support the sector’s ongoing effort to improve the health status of New Zealanders.

How is the NHI number used?

The NHI number is used by:

  • your GP, Pharmacist and community laboratory
  • a hospital’s community health service, to co-ordinate and manage its visits, such as community health nursing or mental health contact visits
  • screening programmes, to coordinate and manage the programme; this includes tracking and contacting clients and potential clients, and managing clinical information
  • public health units, to coordinate and manage patient-based public health services such as immunisation and school dental services.

The NHI number is used to uniquely identify information in national databases that are accessible to approved health providers. There are two databases:

  • The Medical Warnings System (MWS). The MWS is designed to warn providers of any known risk factors that may be important when making clinical decisions about individual patient care. This data can be accessed only by using the NHI number.
  • The National Immunisation Register (NIR). The NIR is designed to assist vaccinators to increase New Zealand’s immunisation coverage through timely access to immunisation histories.

The Ministry of Health uses a coded form of the NHI number to uniquely identify health and disability support events on statistical databases. The databases are used to:

  • produce statistical publications
  • meet international reporting requirements
  • assist with developing policy
  • facilitate research
  • support the planning of health and disability support services, including health needs assessment
  • assist with monitoring the performance of health and disability support services.

An encrypted form of the NHI number is used in statistical databases to help protect the privacy of individuals while enabling data from different places to be linked.

Can I have my details changed on the NHI?

Yes, your details on the National Health Index can be changed. The best approach is to do this via your regular health professional. They will either be able to directly update your details on the National Health Index or if they do not have update access they can contact the Ministry of Health who can make the changes for them.

Where is NHI information stored?

NHI information is stored in the National Health Index which is a database maintained by the Ministry of Health.

Who has access to the National Health Index?

Only health agencies that are involved in providing health services can access and use the information on the National Health Index. The Ministry of Health manages the National Health Index under the guidance of the Health Information Privacy Code 2020.

How will possible duplicate NHI numbers be eliminated?

Sophisticated software implemented in 2013 actively searches for duplicate records. This software is continually configured to improve the recognition of duplicates, and a team of analysts use tools to identify and resolve possible copies. Reducing the number of duplicates will increase the quality of the NHI. Duplicate reduction has two aspects:

  • finding and linking existing duplicates
  • reducing the creation of new duplicates, including:
    • new data elements to improve the ability to uniquely identify individuals
    • training on searching the National Health Index to reduce the number of new registrations of individuals already existing on the National Health Index
    • increased monitoring to identify agencies that are creating duplicate NHIs numbers
    • continually improving the search engine to improve the ability to find an existing NHI number.

Do I need an NHI number?

Yes. Health providers need the NHI number and will assign one to you if you do not already have one. This is permitted under the Health Information Privacy Code 2020.

Under this Code health providers must tell you if they are collecting information and will be using it to register you on the National Health Index or update information already associated with your NHI number.

Can my NHI number be used for other purposes?

NHI numbers can only be used for the purpose they were created for or as otherwise required by law. Please see the section above ‘What is the NHI used for?’ for more information on the uses of the NHI.

How is the National Health Index accessed?

The National Health Index is accessed directly from your GP or pharmacies or the hospital patient management system.

Some authorised providers can access the National Health Index through a standalone interface provided by the Ministry called the Health Identity User Interface (HIUI).

More information will be available online shortly.

How does the NHI merge information?

The NHI number ties together all patient documentation and internal patient systems in hospitals. The NHI number is on patient labels, which are used on most items of patient documentation; from pharmaceutical labels to discharge summaries. Usually, the hospital’s central patient management system, which manages admissions, discharges and transfers of patients, is linked to other clinical systems such as the laboratory, the pharmacy and dental and surgical booking by means of the NHI number.

Where regional services exist, such as centralised diagnostic services, health providers may receive the diagnostic results electronically from an external source. The NHI number is used to ensure that the results are associated with the correct patient.

Security and privacy

Who has access to NHI information?

Access to the NHI is restricted to health professionals and agencies governed by the Health Information Privacy Code. Each organisation that has access to this information accepts their obligations under the Privacy Act 2020 and the Health Information Privacy Code 2020 to only access information about patient’s they are treating and are authorised to do so. Every NHI transaction is logged. Details are recorded of who accessed the National Health Index and when, what they did, and which NHI number they looked at. An audit programme monitors whether access was justified and whether it was used for legitimate purposes.

Who can change my information?

DHBs, GPs and the Ministry of Health are current organisations able to change NHI details; they have full access and are able to change personal information such as alternative names and contact details, as well as update medical warnings. All Ministry of Health staff who access the National Health Index have to sign a confidentiality agreement before using it. For most users, however, viewing the National Health Index is a read-only process, which allows them to search for NHI numbers and see the information but not change anything.

Is my NHI number secure?

The Privacy Act 2020 protects personal information and gives you a measure of control over your personal information. The Health Information Privacy Code 2020 was approved by the Privacy Commissioner to take into account the special factors and characteristics of health and disability services and strengthen the focus on privacy. Your NHI number helps keep your health information private. Personal information with your NHI number included is more secure than the same information with your name and address on it.

Is the National Health Index secure?

Yes, the National Health Index is secure. All NHI messages are protected by 128-bit encryption as they travel over a ‘virtual private network’ (VPN) called the Health Intranet. The computer system is kept in a secure government data center and the information is duplicated on another data center in another building. Both systems have disaster recovery plans in place to ensure that the data held on the National Health Index is always kept secure and complete.

How can I find out more about NHI privacy?

The NHI complies with all Privacy Act and Health Information Privacy Code requirements, which can be viewed here: