Unlike some countries where paying down a mortgage early is simply free, most Canadian closed mortgages come with a specific annual limit on how much extra you can pay without penalty — a prepayment privilege, typically 10-20% of the original principal per year. Go past it, and the penalty on a fixed-rate mortgage can be a genuinely large number.
How the Privilege Works
Lenders set an annual prepayment privilege, commonly 15% or 20% of the original loan amount (not the current balance), resetting each year on your anniversary date. Some lenders also allow a separate "payment increase" privilege — raising your regular payment amount by a percentage, which compounds the effect over the term.
Worked Example
On the $520,000 original loan amount, with a 15% annual prepayment privilege:
| Item | Amount |
|---|---|
| Original loan amount | $520,000 |
| Annual privilege (15%) | $78,000 |
| Lump sum applied in year 3 | $30,000 (within privilege) |
| Approx. interest saved over remaining term | ~$14,000-$18,000 |
| Approx. time cut off amortization | ~1.5-2 years |
That $30,000 lump sum stays comfortably within the $78,000 annual allowance, so it's applied penalty-free, directly reducing principal.
What Happens if You Go Over the Privilege
On a closed, fixed-rate mortgage, exceeding your annual privilege triggers a penalty calculated as the greater of:
- Three months' interest on the excess amount, or
- The Interest Rate Differential (IRD) — roughly, the difference between your contract rate and the current rate the lender could get on a similar mortgage for your remaining term, applied to the excess amount and remaining time.
The IRD can be substantial when rates have dropped significantly since you signed — which is often exactly when someone is motivated to prepay or refinance in the first place, since a bigger IRD often shows up alongside a lower available rate.
Common Mistakes
Borrowers frequently assume their prepayment privilege resets on the calendar year — it typically resets on the mortgage's anniversary date instead, which can mean unused privilege from one year doesn't carry over, and a large prepayment made just before the anniversary might be smarter timed just after it, to get a fresh allowance sooner.
Borrowers also confuse "prepayment privilege" with "no penalty ever" — the privilege is specifically an allowance, not a full elimination of penalties; anything beyond it is still subject to the IRD or three-month-interest calculation.
A third mistake: not checking whether unused privilege is "use it or lose it." Most lenders don't allow you to bank an unused 15% allowance from one year into the next — it simply resets.
Where This Calculator Has Limits
It can't calculate your exact IRD penalty without your lender's specific posted rates and remaining term, since that formula is lender-proprietary and varies. It also assumes a standard closed mortgage — open mortgages typically allow unlimited prepayment without penalty, at the cost of a meaningfully higher interest rate.
Frequently Asked Questions
Is there ever truly no penalty for prepaying?
Yes — open mortgages allow unlimited prepayment penalty-free, though they carry higher rates than closed mortgages as a tradeoff.
Does my privilege apply to lump sums, higher regular payments, or both?
Depends on the lender — many separate these into two distinct privileges (e.g., 15% lump sum plus a 15% payment increase allowance), so check your specific mortgage documents.
Can I estimate my IRD penalty myself?
Roughly, but not precisely — your lender's exact posted-rate comparison table is needed for an accurate number; online estimates are directional only.
Does prepaying always make sense?
Usually it reduces total interest paid, but it's worth weighing against other uses of that cash — paying off higher-interest debt first, or maintaining an emergency fund, can sometimes be the better move.
Do variable-rate mortgages have prepayment privileges too?
Yes, typically similar percentage-based privileges, with a simpler three-months'-interest penalty (no IRD) for amounts exceeding the allowance.
Related Tools
Amortization Calculator · Renewal Planner · Mortgage Calculator
Educational content, not financial advice. Prepayment privileges and penalty calculations vary significantly by lender and mortgage type — confirm your specific terms with your mortgage documents or lender directly. Written by the MortgagePro Global team.