Homes & mortgages
How a mortgage works: principal, interest and payments
Read the parts of your mortgage payment and separate the contract from the repayment timeline.
The key idea
A mortgage is a loan secured by property. Your payment usually covers interest and some principal. The term is the current contract period; amortization is the planned time to repay the loan.
What you owe and what you pay
Principal is the loan balance. Interest is the cost of borrowing. A payment can also include property taxes collected by the lender or optional insurance, so use the mortgage statement to identify what actually reduces the loan. Mortgage default insurance, where financed, becomes part of the principal. FCAC: choosing a mortgage
For an ordinary amortizing loan with a stable rate and payment, interest generally falls as the balance falls, leaving more of each payment for principal. That describes the payment’s composition. It does not mean the total scheduled payment automatically falls each month.
Two clocks, one loan
The term ends when the current contract expires. Unless the balance is paid off, you arrange the next term. Amortization extends over the repayment schedule and commonly includes several terms. A fixed rate stays fixed within its term; a variable rate can change during the same contract. Renewal terms and future rates are not guaranteed by today’s payment illustration. FCAC: mortgage terms and amortization
Extra payments have conditions
An extra payment can reduce principal and later interest. First ask what your contract permits: amount, timing, whether a payment increase can be reversed, and any charges. Money paid into the mortgage is no longer cash you can simply withdraw for groceries or a repair. New borrowing is a separate approval. FCAC: paying off your mortgage faster
Interest avoided is a useful cost comparison, but describing every prepayment as a guaranteed investment return hides charges, tax circumstances and the loss of accessible cash.
See it in practice
Read one fictional monthly statement
| Item | CAD |
|---|---|
| Opening principal | $200,000 |
| Payment for principal and interest | $1,300 |
| Interest charged in this example | $800 |
| Principal repaid | $500 |
| Closing principal | $199,500 |
The check is $1,300 − $800 = $500, then $200,000 − $500 = $199,500. The $800 is an invented statement entry, not a rate calculation. There are no other charges, prepayments or arrears here. Your lender’s rate convention, dates and rounding determine actual interest.
Check your understanding
Does a smaller interest portion automatically lower the payment?
No. With a stable scheduled payment, more can go to principal instead. Rate changes, renewal and contract terms can alter the total.
A useful next step
Find the balance, rate type, term-end date and prepayment clause on your statement. Mortgage Payment illustrates payments from entered assumptions; it is not a lender approval or contract interpretation.
Put the proposed payment beside purchase cash and actual household costs, with explicit financing assumptions. Home-Buying Budget Planner. Enter figures manually; no financial values transfer.
Inspect the sources
Primary references checked September 18, 2026. A source check is not professional financial or legal review.
- FCAC: choosing a mortgageCurrent at check · Canada; contracts and lender regulation vary
- FCAC: mortgage terms and amortizationCurrent at check · Canada; contract-specific
- FCAC: paying off your mortgage fasterCurrent at check · Canada; contract-specific