Is child support the same as shared expenses?

No. Child support in Australia is calculated by Services Australia (Child Support) under the Child Support (Assessment) Act 1989 (Cth). It is paid as a regular cash transfer or via the agency. Shared expenses are additional costs the parents agree (or court orders) they will divide — school fees, medical costs, extracurricular activities, school uniforms, etc. The two are separate. Child support flows through one channel; shared expenses are negotiated message-by-message.

What expenses are typically shared between separated parents?

It varies by parenting plan and circumstance. Common shared categories include: school fees and educational expenses, extracurricular activities (sports, music lessons), medical and dental costs not covered by Medicare or private health insurance, school uniforms and books, school excursions and camps, holiday programs, special-occasion costs (birthdays, communions). Day-to-day costs (food, household consumables, normal clothing) are typically each parent's responsibility within their own household.

How should we agree on the percentage split for shared expenses?

Typically 50/50 unless a different ratio is negotiated. Some agreements use the parents' relative income proportions (often documented through child-support assessment outcomes). Some plans differentiate by category — 50/50 for school fees, parent-of-paid-activity covers extracurriculars they signed the kid up for. Whatever the split, write it down clearly in the parenting plan or in a written exchange that becomes part of the record.

What if my co-parent agrees verbally but won't put it in writing?

Send the confirmation message yourself and let silence stand as agreement. 'Confirming we agreed: I'll pay the school excursion fee of $85 and you'll reimburse $42.50 by end of month. Let me know if I have anything wrong.' Their silence becomes confirmation. If they object, that's also captured. Don't proceed with significant spending on the basis of verbal agreement alone.

What if I pay something and they refuse to reimburse later?

Without prior written agreement, you have a harder claim. Some matters can be pursued through the Federal Circuit and Family Court of Australia as part of a property settlement or parenting matter. Some are too small to be worth formal pursuit. The lesson is structural: get agreement in writing BEFORE paying, particularly for amounts where reimbursement matters.

Should I send invoices and receipts on the platform?

Yes. Attach the school invoice, the medical receipt, the activity registration. The platform record then includes both the agreement and the supporting documentation. Don't send these by email separately if you have a platform — keeping everything in one place makes assembly for any future use much easier.

How long should I keep financial records of co-parent expenses?

At minimum, indefinitely while the children are minors and ideally for several years after. Family-law matters can re-open over years. Tax matters can also be relevant — some shared expenses are deductible or claimable in specific contexts. As a rule of thumb: the longer the better, and definitely longer than the formal retention requirements you might think apply.

Money in writing: school fees, medical, and extras — getting it on the record

Money is the second-most-common category of co-parenting friction after handover logistics, and it produces a disproportionate share of escalations to lawyers, mediators, and courts. The reason: money decisions involve clear amounts and clear obligations, and disagreements about who owes what compound over time in a way that pickup-time disputes don't.

This guide is about the specific discipline of documenting financial discussions and agreements with a co-parent. I built It's In Writing for separated parents and the documentation patterns below work on any platform — what matters is the habit, not the tool.

What's in scope

This guide covers shared expenses that the parents have agreed (or court has ordered) to divide. It is NOT about:

Child support. That is calculated by Services Australia and paid through formal channels. It does not require message-by-message negotiation. If you have questions about child support, Services Australia's child support page is the authoritative source.
Property settlement. That is a one-time process governed by Part VIII of the Family Law Act 1975 (Cth). Different documentation discipline applies.
Day-to-day costs within each household. Food, household consumables, clothing for everyday wear — these are typically each parent's responsibility within their own home.

In scope: school fees, medical and dental costs not covered by health insurance, extracurricular activities, school uniforms and books, excursions and camps, special-occasion expenses, and any other shared category your parenting plan specifies.

The five disciplines

Agree before paying

The single most important habit. Never make a significant shared-cost payment without written agreement first.

The pattern:

Receive an expense notification (school invoice, medical bill, activity fee).
Forward to the other parent on the platform: "School excursion fee for [child] is $85, due Friday. We agreed to split these 50/50 — your share is $42.50. Let me know if you'd like me to pay the full amount and you reimburse, or you'd prefer to transfer me your share so I can pay it as one transaction."
Wait for written agreement on payment method.
Pay.
Confirm payment with the other parent: "Paid the $85 to the school today. Looking forward to your $42.50 reimbursement."

This pattern protects you both ways: if they later dispute owing it, the agreement is in the record. If they later claim you didn't tell them about it, your forward message is in the record.

Attach the documentation

Every shared-expense message should include the supporting documentation:

The school invoice or fee notice (PDF or screenshot).
The medical receipt or invoice.
The activity registration with cost breakdown.
Anything else that establishes the source amount.

Attaching documentation does several things:

Authenticates the amount. No "where did the $85 figure come from?" disputes.
Establishes timing. The invoice has a date; the platform message has a date; the relationship is clear.
Protects against your own errors. If you misread an invoice and quoted the wrong amount, the attachment will reveal that, ideally before payment.

Confirm everything in writing

Verbal agreements about money do not exist for documentation purposes. If you agree verbally — at handover, on the phone, at a school event — follow up with a written message within a few hours.

"Just to confirm what we discussed today: the orthodontist consultation is $250, and we agreed to split it 50/50. I'll pay it next week and send you the receipt; you'll transfer $125 once you've seen the receipt. Let me know if I have anything wrong."

The follow-up serves the same purpose as for handover discussions — it converts the off-platform conversation into an on-platform record. Silence after a follow-up becomes confirmation.

Don't escalate the message

Money messages are one of the highest-temperature categories. The temptation is to mix the financial detail with grievance:

"I've ALREADY paid for the soccer registration AND the new boots, so it's only fair that you actually contribute to ANYTHING this term, you keep saying 'next time' but it's been six months."

This kind of message destroys both the record and the request. The other parent's response will be defensive; the message reads badly to a third party; the actual financial discussion gets lost.

BIFF the message instead:

"Hi [Name],

Soccer term fees are $180 due Friday. We agreed to split these 50/50 — your share is $90. Please transfer by Friday and I'll register the kids over the weekend.

Thanks, [Your name]"

If they don't pay, the next message is a brief factual escalation, not an emotional one:

"Hi [Name],

Just following up — the $90 for soccer term fees is now overdue. Could you transfer this week?"

Pattern of this discipline, repeated, builds a credible record. Argument-shaped messages do not.

Keep the receipts

A platform record of the discussion plus the supporting documentation plus the eventual payment confirmation is what makes the financial record useful. Specifically:

Receipts of payment. Bank transfer confirmations, screenshots of payment screens, account statements showing the relevant transactions.
Reimbursement receipts. When the other parent transfers their share, save the confirmation.
A running total (in your own notes, not on the platform) of what is owed each way. Useful for periodic reconciliation.

Don't try to maintain the running total on the platform — it becomes a target for argument. Keep your own records and use the platform for the discussion-and-agreement layer.

Worked example

A typical month, well-documented:

3 March, 9:14am "Hi [Name], school sent the term invoice — $1,240 total covering tuition, sports levy, technology fee. PDF attached. Standard 50/50 split = $620 each. I'll pay the full amount Tuesday and you reimburse $620, sound good?"

[Attachment: School term invoice PDF]

3 March, 11:42am (their reply) "OK, transfer to me by tomorrow"

(Their reply suggests they want to pay the school directly. Brief BIFF response:)

3 March, 11:51am "Sure — I'll transfer $620 to your account today. Then you can pay the full $1,240 to the school. Confirm your account details haven't changed?"

3 March, 12:04pm (their reply) "Same as before"

3 March, 12:19pm "Transferred $620 to your CBA account ending 4527 today, ref: SchoolTerm1. School payment due Tuesday. Could you send me the receipt once you've paid the school?"

5 March, 4:33pm (their reply, with attachment) "Paid - receipt attached"

[Attachment: School receipt]

This is a complete financial record of one shared expense. It includes: the amount, the source documentation, the agreed split, the agreed payment method, the transfer record, and the final payment receipt. If anyone ever asks "did you pay your share of school fees in March?" — the answer is in five messages on one platform.

What about regular recurring expenses?

For expenses that recur on a known schedule (school fees each term, sports registration each season, music lessons each month), it is usually worth establishing a standing arrangement rather than negotiating each time:

"Music lessons are $40/week — I'll continue to pay the teacher direct and you reimburse $20/week monthly in arrears. Confirming we're sticking with this arrangement for term 2?"

A standing agreement, confirmed in writing, reduces the number of message-by-message negotiations. It also creates a clearer record of the cumulative amount owed if reconciliation is ever needed.

What if the other parent simply doesn't pay?

Three escalating responses:

Document each missed payment briefly and factually. "Just noting — your $90 share of soccer fees is still outstanding, due last Friday." Don't escalate emotionally. Note the fact. Move on.
Periodic reconciliation. Every quarter, send a brief summary: "Tallying shared expenses for Q1: I've paid $1,847 in shared costs for the kids; you've paid $290; net balance owed is $778.50 in your direction. Could you transfer this within the next two weeks?"
Formal escalation. If reasonable amounts go unpaid for sustained periods, this can be raised as part of broader family-law matters. Your lawyer can advise on whether the unpaid shared expenses are pursued through court applications, mediation, or written notice. Don't pursue these informally if patterns persist; the documented record you've built is exactly the evidence that makes formal pursuit possible.

Try It's In Writing

If you want a platform built for documenting financial discussions clearly and immutably — Australian, hash-chained, A$39.95 per parent per year — start free. Five messages on signup, no card required. Attachments (invoices, receipts) are supported up to 10MB per file.

Money disputes that aren't resolved early compound. The record you build today is what makes them resolvable later.

Related guides

BIFF method for co-parent messages — the writing discipline.
Pickup, drop-off, and the school run — the other high-volume documentation category.
How to document co-parent communication for court — the broader playbook.