How Does Your Credit Card Limit Affect Borrowing Power?

By Andrew Paterson

If you’re planning a home loan, your credit card limit matters more than you might expect. It can quietly cut your borrowing power by tens of thousands of dollars before you’ve even applied.

Related: how lenders calculate your overall borrowing power

Related: why credit card limits quietly hurt your borrowing power

Here’s the part that catches most people out.

Lenders assess your full credit card limit, not your balance. A card sitting at $0 still counts against you.

So let’s walk through exactly how this works, what the numbers look like in 2026 and what you can do about it before you lodge.

Why lenders assess the limit, not the balance

When a lender works out how much you can borrow, they look at your income minus your commitments. A credit card is a commitment.

Here’s the logic they apply.

You could draw your card up to the limit tomorrow. So the lender treats the whole limit as money you could owe at any moment.

That means a $20,000 limit is assessed as a $20,000 potential debt, even if you never carry a balance and pay it off in full each month.

Each lender then applies a monthly repayment cost against that limit. Typically it lands between 3% and 3.8% of the limit per month.

• A $20,000 limit at 3% equals about $600 per month in assessed commitments.
• A $20,000 limit at 3.8% equals about $760 per month.

That’s a fixed hit to your surplus income every single month in the lender’s eyes. And surplus income is what drives borrowing power.

What a credit card limit really costs you in 2026

This is where a lot of online guides get stale. Many still quote an old rule that a $10,000 limit costs you around $35,000 in borrowing power.

That figure is out of date for the current rate environment.

To understand why, you need two current numbers.

• The RBA cash rate is 4.35% (effective 17 June 2026, next decision 11 August 2026).
• APRA’s serviceability buffer sits at 3 percentage points (reaffirmed late May 2026).

Lenders don’t assess you at the actual rate you’ll pay. They add that 3% buffer on top.

So with variable rates around 6%, the assessed rate lands near 9%. Higher assessment rates make every dollar of committed expense hurt more.

A worked example (dated 2026)

Let’s make this concrete with a $10,000 limit.

1. The lender assesses roughly 3% of the limit as a monthly commitment. That’s about $300 per month.
2. That $300 per month is money that can no longer service a mortgage.
3. Capitalised at an assessment rate near 9%, that lost monthly capacity works out to roughly $45,000 to $60,000 less borrowing power.

Current sources back this up. Compare the Market found a $10,000 limit reduced capacity by around $47,000 for a $100,000 earner. Finspo puts the rule of thumb at roughly 5 to 6 times your combined limits.

So in 2026 the multiplier is closer to 5x or 6x, not the old 3.5x you’ll still see floating around.

A quick caveat. The exact figure varies by lender because each one uses its own servicing calculator, applying somewhere between 3% and 3.8% of your limit. These are worked examples, not a quote for your situation.

The new 2026 catch: the DTI cap

There’s a second way a credit card limit can bite you now, and most explainers miss it entirely.

Since 1 February 2026, APRA has applied a debt-to-income cap.

Banks can now write no more than 20% of their new mortgages to borrowers whose total debt sits above 6 times their gross income. Your credit card limit counts toward that total debt.

So a limit can hurt you twice.

• It drags down your serviceability (income minus commitments).
• It can push you over the 6x DTI threshold, where a bank may have already used up its high-DTI quota.

This matters because your real borrowing ceiling is the lower of two numbers.

1. The serviceability test (buffered income minus expenses and commitments).
2. The DTI cap (roughly 6x gross income).

Take someone on $120,000 gross income. Their DTI ceiling sits around $720,000, no matter how strong their serviceability looks.

A card limit that tips them over that line can stall the application even if the repayments are easily affordable on paper.

One more thing worth knowing. Non-bank lenders regulated outside APRA’s cap may not be subject to that 20%/6x DTI speed limit. That’s a genuine option a broker can explore when a bank says no.

Does closing a credit card increase borrowing power?

Usually, yes. Reducing or closing an unused card lifts your assessed surplus income, which lifts your borrowing power.

But it’s not always a simple close-everything decision.

Weigh these considerations.

• Reducing the limit often works as well as closing it. Lenders assess the reduced limit, so a $20,000 card cut to $5,000 is assessed at $5,000.
• A modest, well-managed card can support your credit history. Under Comprehensive Credit Reporting, a card you handle responsibly shows a track record. Closing every account isn’t automatically the right move.
• Timing matters. Closing an account can shift your credit utilisation and the average age of your file. Effects vary from person to person.

The right call depends on your goals, your income and how your situation may change. That’s the assessment a broker does with you rather than a blanket rule.

Your 3 to 6 month pre-application checklist

If you’re eyeing a purchase this year, the moves you make in the months before you apply carry real weight, much like the steps in a 6-month countdown to getting loan ready. Here’s a practical order to work through.

1. Reduce limits to what you actually use. If you never touch more than $3,000, there’s little reason to carry a $15,000 limit into your application.
2. Close cards you don’t need. Unused accounts are pure drag on serviceability.
3. Avoid new BNPL accounts. Buy now pay later commitments show up in the assessment too.
4. Get it in writing. Ask your card issuer for written confirmation of the reduced or closed limit. Your broker can then evidence it to the lender.
5. Don’t apply for new credit before you lodge. Fresh applications in the months before your home loan can weigh on your file.
6. Keep one modest, well-managed card if it suits you. A clean repayment history under Comprehensive Credit Reporting can help, not hurt.

A limit reduction isn’t always instant on the lender’s side, which is why written confirmation matters. It lets you evidence the change straight away rather than waiting for it to filter through.

Why the lender you choose changes the maths

Two lenders can look at the same $10,000 limit and reach different conclusions.

One assesses 3% of the limit. Another assesses 3.8%. That gap alone shifts your borrowing power by thousands, and it’s part of why a pre-approval can quietly go out of date if your card limits change after the fact.

Some lenders are stricter on card limits. Some are more relaxed. And non-bank lenders may sit outside the February 2026 DTI cap altogether.

This is the part a single bank branch can’t help you with. They can only tell you their own answer.

Working across a broad panel means we can run your exact scenario against lenders with different appetites and find the one that treats your situation most favourably.

Grounding it locally

For a Geelong buyer, this maths gets concrete fast. The median house price in Geelong (postcode 3220) sits around $871,000 as at mid-June 2026, which puts the question of how much income you need to buy in 2026 front and centre.

At those price points, losing $50,000 of borrowing power to an unused card limit can be the difference between an offer that stacks up and one that falls short.

Sorting your credit card limits well before you start inspecting is one of the simpler wins available to you.

The takeaway

Your credit card limit works against your borrowing power whether you use it or not.

In 2026’s rate environment, a $10,000 limit can cut your capacity by roughly $45,000 to $60,000, and it can also push you over the new DTI cap. The exact impact depends on your lender, your income and your full financial picture, in much the same way that the lowest advertised rate isn’t always the cheapest loan.

The good news is that this is one of the most fixable factors in a home loan application. Reduce what you don’t use, get the change in writing and give yourself a few months’ runway.

If you’d like us to run your numbers across our lender panel and show you where your limits are costing you, that’s exactly what we’re here for.

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General information only. This is not financial, credit or tax advice and it does not take your personal circumstances into account.

Figures are worked examples and estimates only. The exact impact of a credit card limit varies by lender, product, income, expenses and household profile, and each lender uses its own serviceability calculator (assessed percentage of the limit typically ranges from about 3% to 3.8%).

Rates, thresholds, scheme rules and lender policies change frequently. The cash rate (4.35%, effective 17 June 2026) and the APRA 3% buffer are current as at the dates cited and are subject to change (next RBA decision 11 August 2026).

Any DTI or scheme references (including APRA’s February 2026 20%/6x DTI cap) are subject to eligibility criteria and lender overlays. Confirm current rules before acting.

Property market figures (Geelong medians) are point-in-time estimates from third-party data providers using differing methodologies. They are not a valuation or a guarantee of value.

Closing or reducing credit accounts may affect your credit file or score. Consider getting personalised advice from a licensed mortgage broker before changing your credit arrangements.

Frequently asked questions

Does a credit card with a $0 balance still affect my borrowing power?

Yes. Lenders assess your full credit card limit, not your balance, because you could draw the card to its limit at any time. A card sitting at $0 with a $15,000 limit is still assessed as a $15,000 potential debt with an ongoing monthly commitment against it.

Is reducing my credit card limit as good as cancelling it?

For serviceability purposes, usually yes. Lenders assess the reduced limit, so cutting a $20,000 card down to $5,000 means they assess $5,000 rather than $20,000. Reducing the limit lets you keep a well-managed card for credit history while still lifting your borrowing power. The best approach depends on your situation.

Does cancelling a credit card hurt my credit score?

It can shift factors on your credit file, such as your credit utilisation and the average age of your accounts. Results vary from person to person. This is general information, so it’s worth getting personalised advice before closing accounts, especially in the months before a home loan application.

How much does a $10,000 credit card limit reduce my borrowing power?

In the 2026 rate environment, roughly $45,000 to $60,000, based on current worked examples. Lenders assess around 3% of the limit as a monthly commitment and capitalise it at a buffered assessment rate near 9%. The exact figure varies by lender because each uses its own servicing calculator applying between 3% and 3.8% of the limit.

How quickly does a credit card limit reduction take effect for my application?

It isn’t always instant on the lender’s side. That’s why it’s important to get written confirmation of the reduced or closed limit from your card issuer. With that evidence, your broker can show the lender the change straight away rather than waiting for it to update elsewhere.