What $300, $500 or $800 a month can change
This illustration holds household income at $120,000 and changes only the monthly payment for debts outside the mortgage. The result is an income-based mortgage ceiling, not a maximum home price. Down payment and property eligibility still have to fit.
| Other debt / month | Income-based mortgage ceiling | Limiting ratio |
|---|---|---|
| $0 | $507,500 | Housing costs (GDS) |
| $300 | $507,500 | Housing costs (GDS) |
| $500 | $507,500 | Housing costs (GDS) |
| $800 | $462,800 | Housing + debts (TDS) |
| $1,000 | $432,900 | Housing + debts (TDS) |
$120,000 gross annual income; 4.50% example contract rate, stress-tested at 6.50%; 25 years; Canadian semi-annual compounding; monthly payments; $4,200/year tax and $150/month heat; no condo fees. GDS 39%, TDS 44%. Mortgage amounts rounded down to $100. No down-payment or property-price test is included in this table.
Why the first few hundred dollars may change nothing
Qualification has two ceilings. GDS limits housing costs relative to income. TDS limits housing costs plus other debt payments. The lower ceiling wins.
In this example, a small debt payment fits inside the spare TDS room, so housing costs still set the limit. As debt payments rise, TDS becomes the tighter constraint. This is why ‘every $500 car payment costs $100,000 of mortgage’ is not a reliable rule for everyone.
The table uses the same underlying calculator as our qualification tool. It shows the binding ratio so you can see why the result changes, rather than assuming all debt repayment creates the same benefit.
Pay off the car or keep the down payment?
Imagine you have $80,000 saved and a $20,000 car-loan payout. Clearing the loan leaves $60,000 before closing costs. The lender may count less monthly debt, but you also have $20,000 less to put into the property. On the same home, the mortgage may need to be larger and its insurance cost may change.
Compare two complete scenarios: keep the loan with your original down payment; or repay it with the remaining cash and a confirmed lower qualifying debt payment. Include the minimum down payment, insurance premium, closing costs and a reserve in both. Do not choose based on the mortgage ceiling alone.
- Get the actual payout balance, fees and payment schedule from the creditor.
- Ask whether a partial repayment reduces the required payment or only shortens the loan.
- Confirm the lender’s evidence requirements for a paid-off debt.
- Re-run the property price and cash-to-close calculation before moving money.
Buying a car before your mortgage closes
A new loan or lease changes the finances behind your mortgage application. Tell the broker before signing, even if you already have a pre-approval. A lender may reassess the file before funding. An affordable car payment in your daily budget can still change mortgage eligibility.
If you need a vehicle now, ask for a side-by-side calculation using the proposed payment, cash purchase cost or lease terms. Do not hide an obligation or assume it will be ignored because it is new.
What to bring to a useful mortgage conversation
Bring each debt’s balance, required payment, remaining term and payout amount. Add your gross income evidence, savings available and estimated closing costs. These facts make it possible to compare repayment against keeping cash without guessing.
Our BC mortgage team can help review the trade-off. The public tools and examples are available across Canada for education; the receiving lender makes the approval decision.