A common debt reducer reduces the liability a lender counts against an applicant when another person can demonstrate responsibility for part of the repayments. The applicant remains legally liable for the debt, and the account stays on their credit file.
The deciding questions are who shares the loan, how the other person funds their share and whether the lender accepts that arrangement. A repayment history alone does not establish that every lender will exclude the same amount.
How a Common Debt Reducer Works
The lender starts with the shared commitment, assesses the other person's ability to meet their part and attributes the accepted remainder to the applicant. This changes the liability used in loan serviceability. It does not change the loan contract.
Keep repayment allocation separate from ownership. Owning half a property does not automatically mean a lender counts half its mortgage repayment. A lender can assess the full debt even when someone else has been paying it.
Evidence Lenders Ask to See
Build the evidence around the payment trail and the other person's capacity to keep paying. A declaration can explain the arrangement, but it does not replace the lender's income and liability assessment.
- Collect loan statements showing the balance, required repayment and actual payments.
- Match those payments to statements from the account the other person pays from. Transfers from the applicant can change what that evidence proves.
- Collect a continuous repayment history covering the lender's required period. Distinguish ordinary account-conduct requirements from any separate requirement for proving who pays.
- Provide the other person's income evidence, their liabilities and the lender's consent or financial-position form where required.
- For a separation, include relevant orders or agreements and evidence of the ongoing payment arrangement. For business-serviced debt, include company statements and supporting financials.
Lenders differ on eligible relationships and whether the other person must share the existing loan. They also set their own evidence requirements. There is no universal three-month or six-month common debt reducer rule.
Debts Where Lenders Apply It
Joint Home Loans
For a jointly held home loan, record who occupies the property, who owns the security and who makes the payments. After separation, the legal agreement and bank transactions must support the arrangement described in the application.
A former partner is not automatically eligible under a policy restricted to a current spouse or de facto partner. Macquarie's published policy is restricted to spousal relationships. It requires full assessment of joint commitments with non-spousal parties.
Business-Serviced Debt
Where a company pays a debt, establish the borrower, any personal guarantee and whether the business can sustain the repayments. Check company statements against the applicant's personal obligations and the income used in servicing.
Counting income before a business debt expense while excluding that same expense can overstate capacity. A personally held personal loan needs its own assessment. Business payments into the account do not by themselves convert it into an excluded liability.
Which Lenders Apply a Common Debt Reducer
Macquarie and AMP Bank publish common debt reducer arrangements. Their documents describe different assessment requirements, so treat each row as a specific policy pathway.
| Lender | Lender's Name for Treatment | Debts Covered | Evidence Period | Share Excluded |
|---|---|---|---|---|
| Macquarie | Common debt reducer | Joint commitments with a non-applicant spouse or de facto partner | Up-to-date statement for external joint debt, with account conduct assessed under Section 2F | The portion supported by the spouse's verified servicing capacity, with no automatic equal split |
| AMP Bank | Common debt reducer principles | Joint home loan, investment loan or line of credit with a non-borrowing related party | Contribution declaration and financial position assessed with the application | Apportioned contribution accepted for servicing |
Macquarie's policy guide requires a verified household assessment and an applicant assessment. Its credit guidelines set the account-conduct requirements. Keep these distinct from proving the spouse's contribution.
AMP Bank's forms page identifies its common debt reducer process. The related-party declaration records the monthly contribution and confirms that each borrower remains liable for the whole debt.
Use the lender policy guides to compare the wider credit rules alongside this treatment.
Worked Serviceability Example
This illustrative file involves a jointly liable applicant whose former partner pays half the mortgage. Assume the proposed lender accepts the former partner arrangement and six months of matching payment evidence. These are example assumptions, not a named lender's eligibility or evidence rule.
The joint mortgage balance is $400,000 with 25 years remaining. At an assumed assessment rate of 9% per year, monthly principal-and-interest repayments are approximately $3,400, rounded to the nearest $100 for this comparison.
The contractual repayment is $2,577 a month, approximately the repayment at 6%. Statements show the former partner contributes $1,288.50 each month. The example lender excludes 50% of the assessed commitment, $1,700.
| Monthly Assessment Item | Accepted 50% Allocation | Full Debt Counted |
|---|---|---|
| Surplus before the shared mortgage | $4,000 | $4,000 |
| Shared mortgage counted | $1,700 | $3,400 |
| Remaining surplus | $2,300 | $600 |
Using rounded figures, the allocation increases monthly surplus by $1,700. Hold all other assumptions constant to isolate this effect. Actual lenders can also differ in their assessment rate, accepted income and expenses.
The improvement is assessment headroom, not a borrowing-limit quote. A lender's debt-to-income rules can apply separately to the outstanding balance.
When the Reducer Will Not Help
A common debt reducer cannot repair a weak credit score or remove repayment risk. If the other person stops paying, the applicant's legal obligations continue.
The treatment also fails where the relationship is ineligible, the supporting person cannot service their share or the documents contradict the claimed arrangement. Correct liability treatment alone cannot overcome insufficient income or unacceptable credit conduct.
Before submitting the application, run the file under the lender's current policy and compare it with a full-debt assessment. Keep both outputs with the evidence so the lending recommendation reflects the accepted treatment and the client's repayment exposure.
