Separated parents may apply to the CSA for an assessment of child support. This is assessed on the basis of a child support formula.

The child support formula calculates each parent's contribution towards the costs of raising a child based on the combined incomes of both parents and the care arrangements for the child. The Costs of Children Table provides how much children cost by reference to both parents' combined income, the age and number of children (s.5 & Schedule 1 Assessment Act).

Parents will be required to notify the CSA about the care arrangements for the children. This may be in the form of an agreement (written or verbal), parenting plan or court order.

"Regular care" is defined as having between 14% and 35% care of a child, and "shared care" is defined as having between 35% and 65% care of a child (s.5).

An amount for self-support of each parent and the costs of children from new families are also taken into account. The Costs of Children Table and the online Estimator can be found on the CSA website at www.csa.gov.au.

As of July 2009 same-sex couples can apply for child support.

If a parent is on low income, for example Centrelink benefits, minimum child support of $7.12 per week to each family is payable (up to a maximum of three families). This amount is subject to indexation (s.66 Assessment Act) and the parent will be advised in writing of the new amount. The minimum rate will not apply if there is a departure determination, court order or agreement in place (s.66(8)) or if a parent has at least regular care of one or more of the children (s.66(1)).

Further, a parent who declares a low income but is not on an income support payment may be assessed to pay a fixed rate of $23.58 per child per week (subject to indexation) up to a maximum of three children. This is called a "fixed assessment" and may apply to parents who minimise income to avoid child support.

The maximum child support payable is also known as the "cap". The maximum child support is applied to the combined income of both parents up to 2.5 times the annual equivalent of all Male Total Average Weekly Earnings (MTAWE) and calculated using the Costs of Children Table.

In 2011, the MTAWE is $61,781. For 2011, the combined income of both parents is capped at approximately $154,453 per year. For example, on the maximum income of $154,453 per year, the costs of three children over 13 years of age are capped at $43,864 per year.

Parents may make a child support agreement and can choose to organise collection themselves or collection by the CSA. Parents can make agreements regarding the way in which child support is paid, for example through periodic cash payments, non-cash payments (see: "Collecting child support", below) or a lump sum payment (including by way of property settlement).

There are two types of agreements: binding child support agreements and limited child support agreements. The main difference between them is that parents are not required to obtain legal advice before entering into a limited child support agreement. The amount of child support payable in a limited child support agreement must not be less than the amount calculated in the CSA assessment.

Agreements must be in writing and signed by the parties (ss.80C & 80E Assessment Act).

If a parent is in receipt of Family Tax Benefit A, the amount of Centrelink benefits the parent will receive is based on the child support formula amount as though the child support agreement was not in place. This is called a "notional" assessment and is worked out by the CSA.

If a parent has not lodged a tax return or provided information to the CSA regarding their income, the CSA may determine an appropriate income to be used in making a child support assessment (also known as "default income"). The CSA may change the income used in an assessment if the parent provides information regarding their income or if they lodge a tax return (s.58 Assessment Act).

Adjustments to a parent's income, in some instances, are not able to be backdated by the CSA (s.58A).

In some circumstances, if a parent's income is expected to or has reduced by at least 15%,they may give the CSA an estimate of their current income (s.60). If the estimate is accepted, CSA may change the rate of child support. A penalty may be imposed if a parent underestimates their income (s.64AA).

If there are any mistakes or errors in the assessment (whether or not made by the CSA or due to false or incorrect information provided to the CSA), notify the CSA as soon as possible so that the assessment may be changed (s.75).

A parent's change of circumstances may affect an assessment of child support. Examples include birth of another dependent child, unemployment, or change to the arrangements for spending time with a child. You should let the CSA know as soon as changes occur as some changes may not be backdated.

If separated parents reconcile, the CSA will suspend child support liability under an assessment (s.150E) for six months. The CSA will amend the administrative assessment depending on when they are notified/become aware of the change in care arrangements.

Post-separation costs: Following separation and in some circumstances, either parent may apply to the CSA to exclude additional income earned to meet post-separation costs. To apply, the requirements in section 44 of the Assessment Act must be met.

Either parent may lodge an application to the CSA for change of assessment (also known as "departure determination" or "administrative departure") (s.98B Assessment Act). CSA may also initiate a change of assessment (s.98K). A departure determination may not go back in time (more than 18 months and less than seven years), except with leave of the court (see: "Application to court", below).

It is necessary to show that the case falls under at least one of the reasons below, that there are special circumstances, and that it is just, equitable and proper to change the assessment (s.117(1)). The reasons to apply for a change include:

An objection may only be lodged against some decisions made by the CSA (including some change of assessment decisions). These decisions are listed in section 80 of the Collection Act. Get legal advice if you are unsure about your objection rights.

An objection must be made within 28 days of receiving the notice from the CSA or longer by seeking an extension of time (ss.81 & 82). The other parent is provided with a copy of the objection together with any attached documents. They may respond by opposing or agreeing to it.

The CSA will make a decision on the objection in writing usually within 60 days.

The Social Security Appeals Tribunal (SSAT) is able to review certain objection decisions made by the CSA after 1 January 2007 (s.89 Collection Act). An application may be made to the SSAT within 28 days of receiving the letter or notice of objection decision (or longer, by seeking an extension of time). Contact SSAT on 1800 011 140 or go to the website at www.ssat.gov.au.

Get legal advice to help you apply to the SSAT. If your application is incorrect it may be dismissed. Advice regarding maintenance or child support issues is available through Victoria Legal Aid's Child Support Legal Service on 9269 0408 or on 1800 677 402 (toll free).

The Administrative Appeals Tribunal (AAT) is able to review limited decisions about child support, such as refusal by SSAT to grant an extension of time (s.92(4) Collection Act), decisions relating to a party's percentage of care (s.103VA) and Departure Prohibition Orders (DPO) made by the CSA (s.72(T)).

If a person disputes the CSA's acceptance or refusal of an application for assessment on the basis of paternity issues, they may apply to court. The court will decide the parentage dispute and declare if a person should or should not be assessed in respect of the costs of a child (ss.106A & 107 Assessment Act).

If a person is found to not be the father, the court will also decide if an order should be made for repayment of the child support wrongly paid (s.143). The amount ordered to be repaid is able to be registered for collection by the CSA (s.17A Collection Act).

Application may be made to court if a parent seeks an order for child support to be paid in a lump sum or other non-periodic amount (s.123 Assessment Act).

Where parents cannot agree to change or end a child support agreement, application may be made to the court to set aside the agreement (s.136).

Application for departure from assessment can be made to the Magistrates' Court (state or federal) or the Family Court in limited circumstances. This includes if:

Applications to extend the time to change an assessment beyond 18 months and up to seven years are required to be made to court (s.111).

A court application may also be made to decide a question of law from an SSAT decision (s.110B Collection Act).

A person may appeal to the Federal Court of Australia or the Federal Magistrates Court against the making of a DPO (s.72Q). (See: "Departure Prohibition Order", below).

In some instances, an application may be made to court to enforce unpaid child support (see: "Enforcement Order" below).

An application may be made to the court to temporarily stop assessment, collection or payment of child support (also known as a "stay order"). This can happen where there is an application to the CSA, SSAT or the court, which has not yet been decided. The court is able to make a stay order if it considers that it should do so, taking into account the interests of those who may be affected (s.111C).

You should get legal advice to make sure you have correctly applied to the court, within the time allowed. If your application is incorrect it may be dismissed and the court may order you to pay the legal costs of the other party.

Parents are able to arrange private collection where payments set by an order, assessment or agreement are paid by one parent directly to the other parent. This may happen, for example, by making deposit payments into a parent's bank account. It is prudent to have receipts or a record of payments made.

If private collection arrangements are not working, contact the CSA to take over the collection of child support payments (s.39 Collection Act) (also see: "CSA collect", below).

You can personally take court action to recover any child support that has not been paid (s.113A) (also see: "Enforcement Order", below). However, note that you are responsible for your own legal costs. You must also notify the CSA within 14 days of any court orders that are made.

If requested, the CSA can collect periodic child support, adult child and spousal maintenance payments, and repayment of wrongly paid child support. In some instances, overdue payments may also be collected (s.28A Collection Act). The CSA will need details of the relevant assessment, agreement or court order (ss.23 & 25). Methods of CSA collection include deduction from salary, wages or Centrelink pensions and benefits, collection from another person who holds money on behalf of a parent or interception of tax refunds.

The CSA can impose a penalty for late payments (s.67). See: "Late payment penalties", below.

A parent is able to make direct payments to the other parent or to a third party for the benefit of the child. These are called "non-agency payments" (NAP). Keep proof of payment to send to the CSA, for example bank deposit stubs, receipts or a bank statement. If the CSA is not notified, these payments may not be taken into account.

If both parents agree that the payment was meant as child support, the CSA will credit the amount of the NAP towards child support (ss.71 & 71A Collection Act).

If both parents do not agree that the payment was meant as child support, CSA can only credit the amount if it falls under a special type of NAP specified in regulation 5D of the Child Support (Registration and Collection) Regulations 1988 (Cth) (known as a prescribed payment) and at the time the payment was made the payer has less than 14% care of the relevant children.

Specified payments in regulation 5D are:

CSA will credit specified payments at the rate of 30% of the assessed child support each payment period, if the balance of child support is paid on time.

Where a maintenance order is registered with the CSA, a paying parent can apply to the CSA to have collection of maintenance payments stopped if they are receiving a means tested pension, allowance or benefit. This is called a "low income non-enforcement period" (s.37B Collection Act). This does not end the court order and it only stops the debt with the CSA during that period.

To stop this obligation and any debt under a court order, a parent has to apply to the court on the basis that their circumstances have changed, for example due to illness or unemployment (s.66S FLA).

A parent may not be able to pay child support at the rate assessed by the CSA, causing a child support debt. A parent may be able to apply to pay less. (See: "How to change child support", above).

Where late payment penalties have been imposed by CSA, you may request that they waive the penalties. This is called "remission of penalty". The CSA will consider the circumstances of each case in making a decision (s.68 Collection Act).

If there is a large child support debt and a parent has not made satisfactory arrangements to pay the debt, CSA may prevent them from leaving Australia by making a departure prohibition order (s.72D Collection Act).

Where there are outstanding child support payments either the CSA or a parent can apply to the court for an order for payment of the child support debt. The court can make an enforcement order, such as for seizure and sale of property and attachment of earnings (Chapter 20 Family Law Rules 2004 (Cth)). (Also see: "Private collection", above).