The Three Variables That Déterminé Whether Breaking Your Mortgage Is Worth It
Behind every break-even calculation lie three fundamental variables that, together, déterminé whether breaking a mortgage is a winning strategy or a costly mistake. Understanding the interaction between the mortgage balance, the rate spread, and the number of months remaining in the term is essential for any Quebec borrower considering a refinance. Each of these variables plays a different and sometimes contradictory role in the overall equation.
Variable 1: The Mortgage Balance
The mortgage balance is the foundational variable on which everything rests. It is the surface area to which your rate spread applies — the larger the surface, the greater the potential savings in absolute dollars. On a $500,000 balance, a 1% rate spread generates savings of approximately $416 per month in pure interest. On a $200,000 balance, the same spread generates only $167 per month. Paradoxically, a higher balance also increases the penalty, especially with the interest rate differential (IRD) method. The IRD penalty on a $500,000 balance can easily exceed $15,000 if the spread between the contract rate and the lender's comparison rate is significant and several years remain in the term.
Variable 2: The Rate Spread
The rate spread between your current rate and the new rate offered is the primary profitability driver. It is the most intuitive variable: the larger the spread, the more you save each month. But there is an often-overlooked subtlety. The rate spread also directly affects the IRD penalty amount for fixed rate mortgages. If rates have dropped significantly since your signing, the comparison rate used by the lender will be lower, increasing the differential and therefore the penalty. It is a paradoxical circle: the same condition (falling rates) that makes refinancing attractive is the one that increases the exit penalty.
Variable 3: The Number of Months Remaining
The number of remaining months plays a dual role in the calculation. On one hand, the more months remaining in the current term, the higher the IRD penalty because the differential is applied over a longer period. Some lenders calculate the penalty by multiplying the monthly differential by the number of remaining months. On the other hand, a greater number of remaining months provides a longer window to amortize exit costs. The optimal point generally falls between 24 and 42 remaining months — enough time to amortize costs, but not so much that the IRD penalty becomes excessive.
How the Three Variables Interact: Comparative Scenarios
- Favourable scenario: $400,000 balance, 1.25% rate spread, 36 months remaining. Monthly savings of approximately $417, break-even reached in 18-22 months depending on penalty. Result: clearly profitable.
- Neutral scenario: $300,000 balance, 0.75% rate spread, 24 months remaining. Monthly savings of approximately $188, break-even reached in 20-26 months. Result: marginal, depends on exact fees.
- Unfavourable scenario: $200,000 balance, 0.50% rate spread, 18 months remaining. Monthly savings of approximately $83, break-even reached in 30-40 months. Result: not profitable within the current term.
- Variable rate exception: $350,000 balance, 0.75% spread, 3-month penalty only. Monthly savings of $219, exit cost of approximately $6,500. Break-even of 30 months. Can be profitable if the new term is 5 years.
Using Sensitivity Analysis to Make the Right Decision
Sensitivity analysis involves varying each variable individually to see how it affects the break-even point. Ask your AMF-certified mortgage broker in Quebec to present at least three scenarios: the base scenario with current figures, a pessimistic scenario where costs are higher than expected, and an optimistic scenario where savings are greater. OSFI requires federally regulated financial institutions to clearly disclose their penalty calculation methods, which facilitates modelling these scenarios. If the break is profitable even in the pessimistic scenario, you can proceed with confidence. If it is only profitable in the optimistic scenario, caution is warranted.