Do we both need a lawyer?

For a binding agreement, yes, each party needs independent legal advice and a certificate from their lawyer. For a limited agreement legal advice is not required, though it can still be worthwhile given the agreement's effect.

Can the agreement cover things other than regular payments?

Agreements can include non periodic arrangements, such as meeting particular costs for a child, within what the law allows. How a term is expressed affects how it is enforced, which is one reason careful drafting matters.

What happens after we lodge the form?

Services Australia checks the agreement against the acceptance requirements and tells both parties whether it has been accepted. Once accepted, it changes how child support is assessed or collected in line with its terms.

Can we end or change an accepted agreement later?

Only through the processes the law provides, which differ by agreement type. A new agreement, a court order, or specific termination rules can apply, so check with Services Australia before assuming an agreement can simply be dropped.

Other

Fill Out Child Support Agreement Form (CS1666) Online

Child support agreement form

Services Australia

Records a binding or limited child support agreement between parents for acceptance by Services Australia.

Reviewed July 2026

How it works

1
Open the form. The official PDF loads straight into the editor, no download needed first.
2
Fill it out in the editor. Click anywhere to type, add checkmarks and place your signature.
3
Download your PDF. Save the completed form, ready to print or submit.

Form CS1666 is the Services Australia child support agreement form. Parents, and in some cases non parent carers, use it to record a private agreement about how child support will be paid, then lodge it with Services Australia for acceptance. An accepted agreement replaces or modifies the formula assessment with the arrangements the parties have chosen themselves.

You can fill out CS1666 directly in the Universal PDF editor. Enter the parties' details, the children the agreement covers, and the agreed child support arrangements, then download the completed PDF for signing. Agreements are formal legal documents, so check the signing and advice requirements that apply to your agreement type before lodging.

What is Form CS1666 used for

The form documents a child support agreement so Services Australia can assess whether it meets the legal requirements and, if accepted, give effect to it. Agreements can deal with periodic payments and can also cover other forms of support, such as payment of specific expenses, depending on what the parties include and what the law allows.

Australian child support law recognises two kinds of agreements. Binding agreements offer the most certainty and are harder to end, and each party is required to get independent legal advice, with the advising lawyers providing certificates. Limited agreements do not require legal advice, but a child support assessment must be in place and the agreed amount must be at least the amount payable under that assessment.

Who uses Form CS1666

Parents who have reached their own arrangement about child support use the form to make it enforceable through Services Australia, rather than relying on an informal understanding. A non parent carer who is entitled to child support for a child may also be a party in some circumstances.

Both parties need to understand the type of agreement they are entering and its consequences before signing, because ending or changing an accepted agreement is more involved than changing a formula assessment. Services Australia's website explains the current acceptance requirements for each agreement type.

How to fill out Form CS1666

Prepare the agreed terms before you start, then complete the form together or in turn:

Enter the details of both parties and of each child the agreement covers.
Identify the type of agreement being made, binding or limited, and confirm the requirements for that type are met.
Set out the agreed child support arrangements, including amounts, frequency, and any non periodic support the agreement includes.
For a binding agreement, attach the legal advice certificates from each party's independent lawyer.
Check the start date and any conditions or events the agreement depends on.
Both parties sign and date the form before it is lodged.

How to submit it

Lodge the signed agreement with Services Australia for assessment and acceptance. Documents can generally be uploaded through your Child Support online account via myGov or posted to the address in the form's instructions. Services Australia reviews the agreement against the legal requirements and notifies both parties of the outcome.

If the agreement is not accepted, the existing assessment continues to apply. Because the acceptance rules are technical, especially for binding agreements, review the current guidance on servicesaustralia.gov.au, and consider legal advice even where it is not mandatory.

Frequently asked questions

A binding agreement requires each party to get independent legal advice and lawyer certificates, and it can only be ended in limited ways. A limited agreement does not need legal advice, but an assessment must be in place and the agreed amount must be at least the assessed amount.

Universal PDF is an independent product and is not affiliated with or endorsed by any government agency. Forms are provided from official government sources; always confirm you have the current version before filing.

This form is reproduced from official Australian Government sources, © Commonwealth of Australia, and where applicable is used under a Creative Commons Attribution licence. Universal PDF is not affiliated with or endorsed by any Australian government body; always confirm you have the current version on the official site.