Credit Card Impact Calculator
See how your credit card limits affect your mortgage borrowing power
Important:Many lenders consider your available credit limit when assessing a mortgage application, even when the current balance is low. Each lender's servicing method and treatment of revolving credit can differ.
Shown for reference; this scenario calculates from the available limit.
Adjust this planning assumption. Lender test rates and servicing methods vary.
Illustrative Borrowing-Capacity Effect
$85,811
Scenario based on $20,000 total credit limit
Illustrative Change if Limits Reduced
$77,230
Scenario assumes limits are reduced to $2,000 total
Scenario Monthly Commitment
$600
Calculator assumption: 3% of total limit
Total Credit Available
$20,000
Quick Actions to Improve Borrowing
- • Request credit limit reductions on all cards
- • Cancel unused credit cards
- • Pay off and close store cards
- • Avoid Buy Now Pay Later services
How This Scenario Estimates Credit Card Impact
This calculator applies a 3% monthly commitment to the total credit limit, then converts that commitment into an indicative 30-year loan amount at the test rate you select. It is a planning scenario, not a lender assessment: lenders set their own servicing rates, commitments and credit criteria.
Example: In this model, a $20,000 credit limit produces a $600 monthly commitment and an illustrative borrowing-capacity effect of approximately $85,811.
Why limits matter more than balances
Lenders may assess the risk that the full credit limit could be used, rather than relying only on the amount currently owing. That means an almost-empty card can still affect a lender's affordability assessment.
- Multiple cards compound the effect, even if each balance is low.
- Store cards and buy-now-pay-later accounts can also reduce capacity.
- Unused cards are often worth closing if they are not serving a real purpose.
How to improve borrowing power quickly
Reducing unnecessary card limits may improve a lender's affordability assessment. It does not guarantee approval, and the effect depends on the lender's servicing method and the rest of the application.
- Lower limits before applying rather than after pre-approval starts.
- Close unused cards completely if they are not needed.
- Keep evidence of the reduced limit or closed facility for the lender if requested.
Credit card impact FAQs
Do banks care more about the limit or the balance?
In most cases the limit matters more, because lenders test what repayment could be required if the facility were fully used.
Will lowering my card limit improve borrowing power?
Often yes. Lowering or removing unused credit can reduce the monthly servicing assumption the bank applies, which can improve borrowing capacity.
Should I close unused cards before applying for a mortgage?
Usually that is sensible if you do not need them. Unused credit lines can still count against you, so cleaning them up early can strengthen the application.
Disclaimer: This calculator provides estimates only and should not be relied upon for financial decisions. Actual loan terms, rates, and eligibility may vary. Please contact a Mortgage Lab adviser for personalised advice.
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