Where do I apply for a child support assessment?

Through Services Australia — online via MyGov is the fastest path. You'll need a MyGov account linked to your Child Support service. Phone applications are also available on 131 272, and you can apply via paper form by mail. Online takes about 45 minutes; phone or paper typically takes longer.

What documents do I need to apply?

Tax File Number for yourself, the other parent's Tax File Number if you know it (helpful but not required), each child's date of birth and full name, your bank account details for receiving payments, evidence of paternity if disputed. You don't need pay slips or tax returns at the application stage — Services Australia pulls income data from the ATO once the assessment starts.

How long does it take to get a child support assessment?

Application processing is 14-28 days from lodgement. Services Australia notifies the other parent, gives them an opportunity to respond, then issues the initial assessment notice. The assessment is effective from the date you applied — payments start accruing from that date even if the assessment notice arrives later.

What if the other parent objects to the assessment?

They can object within 28 days of the assessment notice. Services Australia reviews their objection and either confirms, varies, or reverses the assessment. The original assessment continues at the existing amount during the review. If the review changes the assessment, adjustments may be backdated.

Do I have to apply if I'm okay with the other parent paying privately?

For practical reasons — strongly yes. Without a Services Australia assessment, you have no enforceable record of the agreed amount, no automatic indexation, and FTB-A may be capped at base rate (Maintenance Action Test). The assessment can run on Private Collect (parents transfer directly), so getting an assessment doesn't force Services Australia to be in the middle of the money flow — but it does give you the safety net if private arrangements break down.

Can I apply for child support BEFORE separating?

Generally no — child support assumes the parents are living separately. You apply once you've separated (or your relationship has ended). Services Australia treats the application date as the start date for the assessment. If you're considering separation, applying soon after separation is the cleanest path.

How to apply for child support assessment — the step-by-step process

Applying for a child support assessment with Services Australia takes about 45 minutes online plus a 14-28 day processing window. Here's exactly what you need, what happens at each step, and what to do if the other parent objects.

Applying for a child support assessment is the operational starting point for any separated parent. Even if you and your ex have an amicable agreement about money, the assessment is what makes that arrangement enforceable, indexed, and visible to Centrelink for your FTB-A calculation.

This guide walks through exactly what to do, what you'll need, what happens at each step, and the timing.

Before you apply — three things to settle

1. Are you actually separated?

Child support assumes you're living apart. If you're in the same house but in separate relationships ("separated under one roof"), Services Australia recognises that, but you'll need a statement of separation. If you're still considering separation, apply once you've actually separated, not before.

2. Have the children's care arrangements stabilised?

The formula uses each parent's care percentage. If care is still being worked out (changing weekly, parenting plan in flux), the assessment will use a snapshot — and may need re-assessing as care settles. Most parents apply once they've got a stable pattern even if it's informal.

3. Do you know the other parent's contact details?

Services Australia needs to notify the other parent of the assessment. If you don't know their current address, the application is still possible but takes longer — Services Australia uses ATO records and other sources to locate them.

Step 1 — Get a MyGov account and link Child Support

If you don't already have one:

Create a MyGov account at my.gov.au
Link Child Support service (separate from Centrelink — they're linked separately under MyGov)
Complete identity verification (driver's licence, passport, Medicare card)

This is the slowest part if you don't have MyGov already — verification can take a few days. Once done, future Services Australia interactions are all in one place.

Step 2 — Lodge the application

In MyGov → Child Support → "Apply for a child support assessment":

Information you'll provide

Your details — full name, date of birth, address, phone, TFN, bank account
Other parent's details — full name, date of birth, address (if known), TFN (if known), employer (if known)
Each child's details — full name, date of birth, gender, primary residence
Care arrangement — percentage of nights each child spends with each parent (in 14-day fortnight blocks)
Relationship history — when you separated, marriage / de facto status
Income — your current income source (PAYG, ABN, self-employed, Centrelink) — exact figures pulled from ATO later

The online form takes about 45 minutes to complete. You can save and resume if interrupted.

Information you DON'T need at application

Tax returns — Services Australia pulls these from the ATO automatically
Pay slips — only needed if you want a current-year income estimate (separate workflow)
Bank statements — only relevant later if expense evidence is needed
Evidence of separation — only needed if disputed

Step 3 — Services Australia processes the application

Once lodged:

Day 1-3: Application received, basic checks done, your case is created
Day 3-7: Other parent is notified by mail (and SMS if Services Australia has their mobile)
Day 7-21: Other parent has 14 days to respond (provide their details, dispute paternity if relevant, etc.)
Day 14-28: Services Australia issues the initial assessment

The assessment is backdated to the application date, so even if you don't get the notice until day 28, payments are owing from day 1.

Step 4 — Read the assessment notice carefully

The first assessment notice tells you:

Annual payable amount — who pays whom, how much per year
Periodic amount — fortnightly or monthly equivalent
Direction — paying parent and receiving parent
Collection method — defaults to Private Collect; switch via the same MyGov portal
Effective date — when the assessment starts (backdated to application date)
End date — typically end of the current child support period (annual cycle)
Objection window — 28 days to dispute factual errors

See Reading your CS assessment notice for the full walkthrough.

Step 5 — Receive (or pay) your first payment

Private Collect (default)

The two parents arrange the transfer themselves. Most start with a bank transfer aligned to the paying parent's payday (fortnightly typically). Document the first payment carefully — bank statement, transfer reference, date.

Child Support Collect

If the other parent isn't cooperating, you can request Child Support Collect from day 1 of your application. Services Australia arranges collection (wage deduction, etc.) which takes 14-28 days to set up after the initial assessment.

Step 6 — Update Services Australia when things change

The assessment isn't static. Update Services Australia when:

Income changes materially — either parent's. Use current-year estimates if needed.
Care arrangement changes — by more than a couple of nights per fortnight
A child ages out at 18 — usually automatic, but verify
A child ages up at 13 — triggers cost-of-children band shift
A new child is born — into either parent's new relationship (Relevant Dependent Child Amount)
The other parent's situation changes — re-partners, starts a new business, becomes self-employed

Failure to update leaves the assessment at out-of-date figures, which can produce surprises at the next annual cycle or Centrelink reconciliation.

What if you don't know where the other parent is?

Services Australia will attempt to locate them via:

ATO records (their most recent tax return address)
Centrelink records (if they receive payments)
Medicare records
Electoral roll
Other government databases

If they can't be located, the assessment can still proceed but collection options are limited. For overseas parents, see Child support when the paying parent is overseas.

Special case — paternity dispute

If the alleged paying parent disputes paternity, the assessment is paused until paternity is established. This typically requires DNA testing, which Services Australia can facilitate. The receiving parent's evidence (birth certificate listing the father, marriage records, etc.) is usually sufficient to start the assessment; the dispute is resolved separately.

Tax-side implications

The first child support assessment has tax-side effects from the application date:

Paying parent's ATI is reduced by CS paid going forward — this lifts CCS, FTB, and other entitlements
Receiving parent's CS received isn't taxable income but DOES affect FTB-A via the Maintenance Income Test
Both parents should update their Centrelink income estimates with the new CS flow

The Maintenance Action Test guide explains the FTB-A interaction in detail.

How NestWise helps

Free CS calculator — model the formula BEFORE you apply so you know roughly what to expect
Full CS estimator — accurate formula + FTB-A Maintenance Income Test once you're set up
CS Assessment Scanner — scan your first assessment notice once it arrives to extract all the key figures
Your CS picture — running dashboard once the assessment is live

Try the free CS calculator before you apply →