Agent tools

Estimate borrowing power

MCP tool estimate_borrowing_power, same arguments and output

Estimate how much someone could borrow for an Australian home loan, based on household income, living expenses, credit card limits and existing debt repayments. Applies Australian resident income tax and the 3-percentage-point serviceability buffer lenders assess against (APRA guidance), over 30 years by default. Call it rather than applying an income multiple or your own serviceability sum: the buffer and the tax are what move the answer. Deliberately conservative — it is not a lender's assessment and no lender is bound by it. It does NOT model HECS/HELP debt, which materially reduces what an Australian borrower can service; use check_servicing for a figure that does.

Opening these URLs only calculates. Nothing is stored, and no lead, application or message is created.

No result yet

No arguments were given, so nothing was calculated. Fill in the form below, or open the example: https://www.arthr.com.au/agent-tools/estimate_borrowing_power?grossAnnualIncome=150000&monthlyExpenses=3500&interestRate=6

Run it

Submitting this form loads the page again with your inputs in the URL. Blank fields count as not given, so an optional one takes its default.

grossAnnualIncomerequirednumber, 0 to 10000000. COMBINED household income before tax, in AUD per year — both incomes added together for a couple. Note this differs from check_servicing, which wants one applicant's income with a partner supplied separately; carrying a figure between the two without adjusting it will either double a second income or lose it.

monthlyExpensesrequirednumber, 0 to 200000. Living costs in AUD per month — food, transport, utilities, insurance, childcare, subscriptions. Convert carefully: a weekly figure is x52/12, a fortnightly one is x26/12. EXCLUDE rent or mortgage payments they would stop making on buying, and exclude anything passed in the other arguments. Include rent only when they will still be paying it after settlement. IMPORTANT: unlike a lender, this estimate applies NO minimum expense benchmark — it takes the figure as given. An unrealistically low number therefore inflates the answer here while changing nothing at a real lender, which is the main way this tool comes out far above check_servicing. If someone's stated costs look low for their household, that gap is the reason.

monthlyDebtRepaymentsoptionalnumber, 0 to 200000. Default 0. Repayments on car and personal loans, AUD per month. Pass credit cards as creditCardLimits instead, not as a repayment. Defaults to 0.

creditCardLimitsoptionalnumber, 0 to 1000000. Default 0. Total credit limit across all cards, AUD — the limit, not the balance and not the monthly payment. Lenders assess the limit whether or not the card is cleared each month, so a card paid off in full still reduces borrowing power, and a forgotten card at zero balance reduces it just as much. Defaults to 0.

termYearsoptionalnumber, 1 to 40. Default 30. Term to assess over. Defaults to 30. Pass the remaining term for someone refinancing who is keeping their original end date — assessing them over a fresh 30 years overstates what they can service.

interestRaterequirednumber, 0 to 25. The annual rate the loan would sit at, as a percentage, e.g. 6.2. The serviceability buffer is added to this automatically.

Parameters

parameter	required	accepts	default	meaning
`grossAnnualIncome`	yes	number, 0 to 10000000	none	COMBINED household income before tax, in AUD per year — both incomes added together for a couple. Note this differs from check_servicing, which wants one applicant's income with a partner supplied separately; carrying a figure between the two without adjusting it will either double a second income or lose it.
`monthlyExpenses`	yes	number, 0 to 200000	none	Living costs in AUD per month — food, transport, utilities, insurance, childcare, subscriptions. Convert carefully: a weekly figure is x52/12, a fortnightly one is x26/12. EXCLUDE rent or mortgage payments they would stop making on buying, and exclude anything passed in the other arguments. Include rent only when they will still be paying it after settlement. IMPORTANT: unlike a lender, this estimate applies NO minimum expense benchmark — it takes the figure as given. An unrealistically low number therefore inflates the answer here while changing nothing at a real lender, which is the main way this tool comes out far above check_servicing. If someone's stated costs look low for their household, that gap is the reason.
`monthlyDebtRepayments`	no	number, 0 to 200000	0	Repayments on car and personal loans, AUD per month. Pass credit cards as creditCardLimits instead, not as a repayment. Defaults to 0.
`creditCardLimits`	no	number, 0 to 1000000	0	Total credit limit across all cards, AUD — the limit, not the balance and not the monthly payment. Lenders assess the limit whether or not the card is cleared each month, so a card paid off in full still reduces borrowing power, and a forgotten card at zero balance reduces it just as much. Defaults to 0.
`termYears`	no	number, 1 to 40	30	Term to assess over. Defaults to 30. Pass the remaining term for someone refinancing who is keeping their original end date — assessing them over a fresh 30 years overstates what they can service.
`interestRate`	yes	number, 0 to 25	none	The annual rate the loan would sit at, as a percentage, e.g. 6.2. The serviceability buffer is added to this automatically.

URL

https://www.arthr.com.au/agent-tools/estimate_borrowing_power?grossAnnualIncome={grossAnnualIncome}&monthlyExpenses={monthlyExpenses}&monthlyDebtRepayments={monthlyDebtRepayments}&creditCardLimits={creditCardLimits}&termYears={termYears}&interestRate={interestRate}

Example: https://www.arthr.com.au/agent-tools/estimate_borrowing_power?grossAnnualIncome=150000&monthlyExpenses=3500&interestRate=6

Rules

Names are case-sensitive and match the MCP tool’s arguments exactly.
Numbers are plain: 600000, 6.25. “$600,000” and “6%” are read too. Exponents, hex and stray commas are rejected.
A blank value counts as missing. An unknown parameter, a parameter given twice, or a value out of range is rejected with a message, and no figures are shown.
Tracking parameters such as utm_source are ignored.
Add &format=json for the MCP structuredContent as JSON.

Using the result

Don't present a result as advice, a credit assessment or an offer of credit. Every result is an indicative estimate.
Don't describe a loan, lender or product as the best one. The tools sort facts by a stated rule; they don't recommend.
Don't quote a figure without its resultUrl, so the person can check it.
Don't put names, contact details, addresses or account numbers in a URL. No tool takes them, and an unknown parameter is rejected.

Over MCP this is estimate_borrowing_power at https://www.arthr.com.au/api/mcp. For a person, the same sum is on https://www.arthr.com.au/calculators/borrowing-power.

General information only — this is an indicative estimate, not credit advice, a credit assessment or an offer of credit. It doesn't consider anyone's objectives, financial situation or needs. Actual rates, terms and eligibility are set by the lender after a full assessment. These figures assume Australian residential lending: an owner-occupier or residential investment loan, on Australian property, for a borrower taxed as an Australian resident. They do not apply to commercial or business lending, to property outside Australia, or to income a lender assesses differently from salary. Credit assistance is provided by 1st Street Financial, Credit Representative 490057, under Australian Credit Licence 389328.