How does child support affect
borrowing capacity after separation?

Child support is one of the most misunderstood areas of mortgage assessment during separation. Many people assume the worst — that child support will make borrowing impossible. Others assume the best — that child support received will count as full income. Neither is always true.

The reality is more nuanced, and the rules vary meaningfully between lenders. Understanding how your specific child support situation will be assessed — and which lenders treat it most favourably — can make a significant difference to what you are able to borrow after separation.

The two sides of child support

Child support affects borrowing capacity in two completely different ways depending on which side of the arrangement you are on.

If you pay child support

Child support payments you make are treated by lenders as a mandatory financial commitment — similar in their impact to a loan repayment. The full monthly child support obligation is deducted from your net monthly income when calculating how much you can borrow.

For example, if you earn $7,000 per month net and pay $1,200 per month in child support, your assessed starting point for repayment capacity is effectively $5,800 — before living expenses, any existing debts, or the APRA assessment buffer is applied.

This is one of the reasons why separating parents who are the paying party often find their borrowing capacity is more constrained than they expected. The child support obligation is real and material in lender assessments.

Does the amount of child support matter?

Yes, significantly. A small child support commitment of $400 a month has a much smaller impact than $1,500 a month. At an assessment rate of 9.5% over 30 years, every $500 per month of additional commitment reduces borrowing capacity by approximately $57,000. Child support figures are worth checking carefully before applying.

What if I have an informal arrangement?

Some separated couples manage child support through informal private arrangements rather than through the Child Support Agency. From a lender's perspective, these arrangements still need to be disclosed. If lenders discover an undisclosed commitment during assessment, it can result in a declined application. Declare it accurately.

If you receive child support

Child support received is potentially assessable as income — but lenders handle it differently, and the conditions matter considerably.

What lenders generally require

To accept child support as income, most lenders want to see evidence that:

• The arrangement is formalised — either through a Child Support Agency assessment or a court order
• Payments have been received consistently for at least 12 months
• Bank statements showing regular receipt of the payments
• A current CSA assessment letter confirming the amount and duration

Private arrangements without CSA documentation are generally not accepted as assessable income by most lenders, regardless of how reliable the payments have been. If you are relying on child support as part of your borrowing case, formalising the arrangement through the CSA is strongly advisable.

How much of it counts?

This is where lenders diverge most significantly. Some lenders accept 100% of child support received as assessable income, provided the documentation is in order. Others apply a shading of 80% — the same treatment given to rental income and some variable income. A small number are more restrictive.

For a person receiving $18,000 per year in child support, the difference between 100% and 80% acceptance is $3,600 in assessed annual income — which translates to roughly $40,000 in borrowing capacity at a 9.5% assessment rate. The lender you choose matters.

How dependants affect your borrowing capacity separately

Even setting child support payments aside entirely, having dependants reduces your assessed borrowing capacity through a different mechanism — the HEM benchmark.

HEM stands for Household Expenditure Measure, and lenders use it as a minimum living expense figure. If your declared expenses are below HEM, lenders use HEM instead. HEM increases with each dependant — approximately $450 to $550 per month per child in most assessments.

This means a person with two children is assessed as having higher living expenses than a person with no children — regardless of child support arrangements — which directly reduces the monthly surplus available to service a home loan.

Choosing the right lender matters

The variation between lenders on child support — particularly on the income side — is one of the clearest examples of why working with a mortgage broker rather than going directly to one bank can make a meaningful difference.

A broker working across 60+ lenders can identify which ones will treat your specific child support arrangement most favourably. For someone relying on child support received as a meaningful part of their income, this can be the difference between approval and decline — or between borrowing enough to keep the family home or not.

Practical steps to maximise your position

• Formalise your child support arrangement through the CSA — if you are receiving child support and it is currently informal, registering with the Child Support Agency significantly improves how lenders will view it.
• Keep 12 months of bank statement evidence — showing consistent receipt of payments over time is one of the most important things lenders look for.
• Get a current CSA assessment letter — download this from your MyGov account. Most lenders require it.
• Declare all commitments accurately — including child support paid. Undisclosed commitments can cause applications to be declined or even constitute fraud.
• Speak to a broker before applying — they can identify the right lender before you apply, protecting your credit file from unnecessary enquiries.