Legal capacity

When to get legal advice

Get legal advice if you: 

• need to know if a child or adult with an impairment has legal capacity in a particular situation
• want to appeal the appointment of a guardian or administrator
• have questions about an order made by the Queensland Civil and Administrative Tribunal.

How to get legal advice

 If you think an appointed decision-maker has acted improperly, you can make a complaint.

What is legal capacity?

Legal capacity is the ability to make decisions for yourself about your legal affairs. These decisions might include:

• making a binding legal agreement
• suing another person
• making other legal decisions.

There are certain decisions only you can make and must have legal capacity for, such as:

• getting married
• making a will
• voting

To have capacity, you must be able to understand the nature and effect of the decision, freely and voluntarily make the decision, and be able to communicate the decision in some way.

Capacity is different for every situation—you may have capacity for some types of legal decisions and not others. 

Children and legal capacity

Parents of children under 18 are usually considered their legal guardians and may be required to sign legal documents and make decisions on the child's behalf about their long-term wellbeing. These decisions may include religion and schooling.

Sometimes, children can have capacity to act on their own behalf. If they're able to understand the significance of what they're doing, they may be able to make a binding contract for their vital life needs and decisions about their medical treatment.

Each situation should be assessed individually. You should get legal advice.

Adults and legal capacity

Adults with a mental illness or intellectual disability may lack legal capacity if they canʼt make decisions about property or manage their money, medical treatment or lifestyle decisions. Assessing capacity is a complex matter. You should get legal advice.

Having legal capacity

You must have legal capacity to sign a contract, make a will or get married. If it's proven you didn't have legal capacity at the time, then your contract, will or marriage may be invalid.

Buying things from a shop is also a type of contract. If you buy things, such as food or other necessities, without having legal capacity, you're still required to pay for these items under the contract.

Adults must understand the electoral process to have the legal capacity and entitlement to vote.

Appointing a person to make decisions on behalf of someone without capacity

A person may be appointed to make decisions on behalf of someone without legal capacity if:

• an application is made to the Queensland Civil and Administrative Tribunal (QCAT) to appoint a guardian or administrator
• there is an enduring power of attorney, advance health directive or a statutory health attorney.

A litigation guardian may be appointed to act on behalf of a person without legal capacity in legal proceedings.

Applying to QCAT to appoint a decision-maker (guardian or administrator)

Anyone with a personal or professional interest in the affairs of a person (e.g. a relative) can apply to QCAT to appoint a guardian (for personal matters, such as where someone lives or their legal matters not related to property or finance), or an administrator (for financial matters).

If you disagree with QCATʼs decision, you may be able to appeal the decision (in some situations). Get legal advice.

If your circumstances change while under a QCAT order—or there is new evidence to put before the tribunal—you can apply to the tribunal to review the decision. 

Most orders appointing a guardian or administrator are made for a set time period and reviews come up periodically as orders expire.

Making a complaint about an appointed decision-maker 

If you think an appointed decision-maker has acted improperly, you can make a complaint to the Office of the Public Guardian (OPG).

The Public Guardian protects the rights and interests of adults who have impaired capacity. They can investigate complaints about allegations of financial or physical abuse of adults with impaired capacity, and complaints about abuse by an enduring power of attorney. They can also give consent to medical treatment when no statutory health authority is available.

Learn more about making a complaint to the OPG

How to get legal advice

We don’t give legal advice about guardianship but can refer you to other services that may be able to help.

Other places to get legal advice:

• LawRight
• Office of the Public Guardian
• Community legal centres
• Private lawyers

Related information

• Medical consent
• Powers of attorney

Last updated

21 August 2026

Last reviewed

11 July 2023