NDIS and supported and substitute decision-making

The National Disability Insurance Scheme (NDIS) has changed the way services for people with disabilities are funded and delivered. It puts the person at the centre, in charge of setting goals and giving choice and control over the supports and services they receive. Some people with cognitive impairments may need help to make those choices, and a small number will need someone with authority to make decisions on their behalf.

More information about the NDIS, including how to become a participant is available at the NDIS website .

This quick guide is intended to help determine the type of support that might be needed for a participant to manage NDIS’ processes and when guardianship should be considered.

A human rights approach

The NDIS legislation, Tasmania’s Guardianship and Administration Act 1995 and the United Nations Convention on the Rights of Persons with Disabilities each provide a human rights approach to supported and substitute decision-making arrangements.

Collectively, they affirm:

  • Adults with disabilities have the right to make their own decisions, or to participate as fully as possible in decision-making
  • Persons with disability are to be provided with support to help them make and implement decisions
  • Families, carers, other significant people and advocates have a legitimate and important role in supporting people with disabilities with decision-making
  • Substitute decision-making should only be used as a last resort, when all forms of support have been exhausted.
Capacity - the ability to make decisions

Adults are assumed to have the capacity to make a decision unless it is established that the person is unable to understand, retain and weigh up information relevant to the decision, and to communicate the decision by some means.

Capacity is specific to the decision at hand, and can fluctuate depending on a range of factors, including the complexity of the decision, the person’s physical and emotional health, and, importantly, the support they have to make the decision.

Supported and substitute decision-making arrangements

Most people will make some decisions completely autonomously, but have support to make others. At the other end of the continuum, some people will, at times, need someone to make a substitute decision on their behalf.

Providing support to people with a disability if they are unable to make a particular decision is preferable and “less restrictive” than someone making the decision on their behalf.

Informal supports

Family members, friends and other significant people in the lives of a person with a disability can assist or support the making of most decisions, particularly those decisions that are not contentious or conflicted.


Advocates do not make decisions on behalf of the person, rather they will assist the decision-making process by helping explore wishes, preferences and options, and to communicate decisions.

In Tasmania Speakout has been funded under the National Disability Advocacy Program (NDAP) specifically to provide decision-making support to NDIS participants who have impaired decision-making capacity, do not have any family, carers or friends available to assist, and need help to access the NDIS or with the planning process. Advocacy Tasmania is Tasmania’s other key advocacy organisation.


A plan nominee may be appointed by the National Disability Insurance Agency (NDIA) either on the request of the participant or on the initiative of the NDIA itself.  A plan nominee may both support and act on behalf of the participant in relation to the preparation and review of the plan, and/or management of the funding for supports under the plan.


A guardian has legal authority to make personal and lifestyle decisions on behalf of a person with a disability.  Guardians include both enduring guardians (appointed by the person themselves when they had capacity), and guardians appointed by the Tasmanian Civil and Administrative Tribunal (TasCAT) or a tribunal in another state. The decision-making powers of a Tribunal-appointed guardian are generally limited and will be specified in the guardianship order. A guardian can only make NDIS related decisions if they have relevant authority – e.g., to make decisions about support services or where the person is to live.

Administrators and enduring powers of attorney

Administrators (appointed by the Tribunal) and attorneys (appointed by the person themselves) have legal authority to make financial, property and legal decisions on behalf of a person with a disability.

At what points in the NDIS process might a nominee or guardian be required?

At every step of the NDIS planning processes, informal supports should be tried before more formal supports, with substitute decision-making used only as a last resort. The NDIS legislation says a nominee can only act on behalf of the participant if the participant is incapable of acting themselves, with supports.

Plan development, implementation and review

Identifying and expressing wishes, preferences and goals

Family members, carers, and other significant people are usually best placed to support a participant who has limited ability to put forward and promote their goals and wishes.

Where there is no supporter or family members are conflicted, referral to an independent advocate (National Disability Advocacy Program (NDAP) or other) should be considered.

A participant’s support worker can provide information about wishes and preferences, but care needs to be taken where there is a perceived conflict of interest.

Nominees or guardians (with relevant authority) can support the participant to put forward their views and preferences.

Choosing a support coordinator

Support by an informal supporter or an advocate is appropriate to help the participant choose a support coordinator (if included in the plan).  An informal decision made in this way is acceptable if not contentious and if no conflict of interest arises.  A service provider cannot choose a support coordinator on behalf of the participant.

If necessary, a plan nominee or a guardian (with relevant authority) can choose a support coordinator on behalf of the participant.

Choosing service providers

Support coordinators have a key role in sourcing service providers, to give effect to the plan. They cannot choose providers on behalf of the participant, but sometimes there are few alternatives, and sometimes the participant’s preference for a particular provider may be clear, perhaps due to their history and observable reactions to the provider.  Where these choices are uncontroversial, the selection of provider can occur with the implicit agreement of the participant.

Supporters and advocates can support the participant to choose a service provider and to agree to share the plan with those providers. Nominees and guardians can choose service providers on behalf of the participant, only if support for the participant to make those decisions is inadequate.

Signing service agreements

Service agreements are between the participant and service provider. The NDIA does not require a service agreement, but the Australian Tax Office may need one for GST purposes.

A supporter or an advocate can assist the participant to understand the nature and effect of a service agreement, but cannot sign an agreement on behalf of the participant. Relevant accessible information should be provided to assist the participant to understand options and the purpose of the agreement. The participant can indicate their agreement to service provision by a means other than signing the agreement.

A plan nominee, guardian, administrator or an attorney can sign a service agreement or consent to services being provided if it is within the scope of their authority.  A substitute decision-maker is unable to consent to parts of the agreement that relate to conditions or matters for which the participant has control, e.g., treating staff courteously and respectfully.

Provision of services with an unsigned service agreement may occur when it is uncontentious, no conflict of interest exists and there are no risks to the participant.

Plan reviews

A supporter or advocate can support a participant to request a plan review at any time and support them through the process.  If necessary, a nominee or guardian (with relevant powers) can also request and be involved in the plan review meeting and process.

When might an application for guardianship be required?

Guardianship is, by its very nature, the most “restrictive” of all supported and substitute decision-making arrangements.  Applications should be made as a last resort.  A guardian may be needed in the following circumstances:

  • there are important or significant decisions on hand.
  • the person is unable to make the decision themselves, even with support.
  • there is a lack of consensus among supporters about the decision/s or options.
  • there is no relevant substitute decision-maker already in place, and no individual suitable for appointment as plan nominee.
  • advocacy has been tried, or the person would be unable to work with an advocate due to profound disability.
  • there is significant risk to the well-being and safety of the participant.

Information on making an application to the TasCAT can be found on the 'applying for guardianship' page here.  Any interested party can make an application. It must be accompanied by a health care professional report, unless there are circumstances whereby it has not been possible to obtain one.

More information is available on the TasCAT website or by contacting the Office of the Public Guardian on 6165 3444.

A comprehensive guide to the NDIS produced by Victoria’s Office of the Public Advocate in consultation with the NDIS is recommended reading.

Updated: 2nd August 2022