Change of Assessment Reasons in Australia: All 10 Explained

Table of contents

• How to use this guide
• All 10 Change of Assessment reasons
• How to choose the right reason
• Evidence checklist
• Application process and timing
• Frequently asked questions

How to use this guide

This article is for parents trying to work out whether their circumstances fit one of the recognised Change of Assessment reasons. Start with the reason that most closely matches the problem you are actually trying to solve. Then ask two questions: first, does the standard formula miss something important; second, can you prove that with records rather than assertions?

If your issue is really about how the formula works in an ordinary case, start with the child support formula guide. If your issue is that the formula result does not reflect real life, then a Change of Assessment may be the right tool. The broader process is explained in our Change of Assessment guide.

All 10 Change of Assessment reasons

Services Australia uses the official Child Support Guide numbering. Reason 8 is split into 8A and 8B, so you will often see 11 listed items even though the legislation still refers to 10 reasons overall.

Reason 1 — High costs of enabling a parent to spend time with or communicate with the child

This reason is usually raised when a parent faces unusually high contact costs, such as flights, long-distance driving, ferries, or overnight accommodation, just to spend time with the child or maintain communication. It commonly appears in interstate or remote-area parenting arrangements.

The application is stronger when the travel pattern is regular, necessary, and directly linked to time with the child. Typical evidence includes airline invoices, fuel receipts, toll statements, accommodation bookings, and orders or parenting agreements showing the contact arrangement.

Weak applications usually rely on rough estimates or costs that are not clearly tied to time with the child. Ordinary local travel is less persuasive than recurrent long-distance costs.

Reason 2 — High costs associated with the child's special needs

Reason 2 deals with expenses arising from a child's special needs, including physical disability, learning difficulty, mental health treatment, therapy, specialist equipment, or in some cases a recognised special talent that creates genuine additional costs.

Good evidence includes specialist reports, medical letters, allied health invoices, therapy schedules, school support plans, and itemised cost summaries showing what is actually being spent. The key is linking the expense to the child's needs rather than describing a general parenting burden.

Applications tend to fail when the claimed costs are broad household expenses or when there is no clear documentary link between the child's condition and the additional outlay.

Reason 3 — High costs of caring for, educating or training the child in the way both parents intended

This reason focuses on costs both parents intended the child to have, such as private school fees, boarding, structured training, or long-established extracurricular commitments. It is not enough that one parent alone wants the child to continue in a higher-cost setting.

Evidence usually includes enrolment forms, fee schedules, prior communications showing mutual intention, historical payment records, and proof that the arrangement existed before the dispute. Consistency matters more than aspiration.

Weak cases often assume that because a child is currently in private schooling, both parents must have intended it. Services Australia will usually want proof of that shared intention.

Reason 4 — The assessment is unfair because of the child's income, earning capacity, property or financial resources

Reason 4 looks at the child's own financial position, not the parents'. It may apply where the child has substantial income, a trust distribution, a compensation fund, an inheritance, or another meaningful financial resource that affects what support is actually needed.

Evidence can include trust documentation, bank statements, investment records, probate material, or records of regular income paid to the child. The focus is on whether the child's resources make the standard formula unfair in the particular case.

It is usually a weak reason if the child has only modest savings or intermittent part-time earnings that do not materially alter the support picture.

Reason 5 — The assessment is unfair because the paying parent has already paid or transferred money, goods or property for the child's benefit

This reason covers situations where the paying parent has already met a significant part of the child's support through direct payments or transfers. Sometimes this arises through property settlement arrangements, lump-sum contributions, school fees, housing support, or major purchases made for the child.

Useful evidence includes bank transfers, invoices paid directly, settlement documents, receipts, and written agreements explaining the purpose of the payment. The stronger the paper trail, the easier it is to show the payment was truly for the child's benefit.

Reason 5 is often weak where the payments were informal, mixed with adult expenses, or made without any clear contemporaneous record.

Reason 6 — High childcare costs for the child

Reason 6 concerns significant childcare costs, usually where those costs are necessary because a parent is working, studying, or otherwise genuinely unable to care for the child during those periods. It is often relevant for younger children whose care costs are not fully reflected in the formula outcome.

Evidence typically includes childcare invoices, attendance records, employment rosters, study schedules, and proof of who is paying the fees. If the childcare is irregular or discretionary, explain why it is still necessary.

Weak applications usually fail to separate necessary childcare from preferred convenience arrangements or fail to prove the actual amount being paid.

Reason 7 — A parent's necessary expenses significantly reduce their capacity to support the child

Reason 7 deals with necessary expenses that materially reduce a parent's capacity to contribute. This can include unusually high health costs, disability-related expenses, or other unavoidable commitments that are not already built into the formula.

Good evidence includes invoices, medical certificates, payment plans, loan statements tied to the necessary expense, and a clear budget showing why the expense is unavoidable. The distinction between necessary and discretionary spending is critical.

Applications are often refused where the parent relies on lifestyle expenses, ordinary consumer debt, or costs that appear self-created rather than necessary.

Reason 8A — The assessment is unfair because of the income, property or financial resources of one or both parents

Reason 8A is one of the most important reasons in practice. It applies where taxable income does not tell the whole story because a parent has access to assets, company resources, trust income, retained profits, or other financial resources that are not properly reflected in the formula income figures.

This reason commonly appears in cases involving business owners, trusts, low declared salaries, substantial assets, or living standards that do not match reported income. Evidence can include company financial statements, trust deeds, property searches, loan accounts, bank records, and transaction histories.

Reason 8A is weak when the allegation is speculative and there is no documentary basis for saying the parent has access to extra resources.

Reason 8B — The assessment is unfair because of the earning capacity of one or both parents

Reason 8B addresses earning capacity rather than current declared income. It is often used where a parent is voluntarily unemployed, under-employed, or has changed work arrangements in a way that depresses income without a satisfactory explanation.

Services Australia usually looks closely at the parent's work history, qualifications, previous earnings, current hours, health, and caring responsibilities. Useful evidence includes prior tax returns, payslips, resumes, job ads, industry pay data, and material showing the parent could earn more.

This reason is weaker where reduced work is justified by health issues, genuine care commitments, or credible labour market constraints. It is not enough simply to say someone could be earning more.

Reason 9 — A parent's capacity to support the child is significantly affected by their duty to maintain another child or person

Reason 9 concerns legal or practical obligations to support another child or person, where those obligations materially affect the parent's capacity to contribute under the standard assessment. It can overlap factually with blended-family issues, but the emphasis is on the external maintenance duty itself.

Evidence may include court orders, care arrangements, medical or dependency documents, and financial records showing the ongoing support burden. The point is to prove that the obligation is real, current, and financially significant.

Weak applications tend to rely on general statements about family pressure without showing a concrete legal or practical maintenance obligation.

Reason 10 — A parent's responsibility to maintain a resident child significantly reduces their capacity to support the child

Reason 10 is commonly raised when a parent now has a resident child in their household and the standard formula does not adequately reflect the financial impact of maintaining that child. In practice, this is often the reason people have in mind when they ask whether a new baby reduces child support.

Helpful evidence includes proof that the resident child lives with the parent, household budget material, birth records, and evidence of the actual ongoing costs of care. The stronger applications show why the resident-child costs significantly affect capacity rather than merely increasing expenses in a general sense.

Reason 10 is often weaker when the child is not truly resident with the parent or when the application does not explain how the household change materially affects support capacity.

How to choose the right reason

Many applications fail because the facts are not organised around the right reason. If your issue is high travel or communication cost, start with Reason 1. If the problem is special medical or developmental expense, use Reason 2. If the problem is not cost but hidden wealth or low declared income, you are usually looking at Reason 8A or 8B.

Where more than one reason may apply, lead with the best fit and then explain the alternatives briefly. An application that tries to rely on every possible reason without clear structure is usually harder to assess and less persuasive.

If you are unsure whether the issue is the formula itself or the fairness of the outcome, run the numbers first in the child support calculator. That gives you a baseline before you ask Services Australia to depart from it.

Evidence checklist

Services Australia decides Change of Assessment matters on evidence, not on suspicion alone. The most useful applications attach a clear chronology and then group the documents under the relevant reason.

• Travel and communication costs: flights, tolls, fuel logs, accommodation, phone records, parenting orders
• Special needs: specialist reports, therapy invoices, medication costs, learning support plans
• Education or training: enrolment forms, fee schedules, past payments, messages showing shared intention
• Childcare: invoices, attendance statements, work rosters, study timetables
• Income and resources: tax returns, bank statements, company accounts, trust documents, property records
• Earning capacity: job ads, resumes, prior payslips, prior tax returns, industry salary data
• Resident child or other dependants: birth records, care arrangements, household budgets, court orders

Application process and timing

A Change of Assessment application is usually made through Services Australia. The other parent is given an opportunity to respond, both sides can provide supporting material, and a decision-maker then determines whether changing the assessment is just and equitable.

If your case involves hidden income, companies, trusts, unusually high-value assets, or disputed medical and educational costs, it may be worth reading when to see a lawyer before you lodge material that cannot easily be corrected later.

Frequently Asked Questions

Related guides

• Change of Assessment guide
• When to see a lawyer
• Child support formula