Money paid into a mortgage saves interest at the mortgage rate, but you can’t take it back out when you need it. Money in an emergency fund earns less, but it’s there when the furnace fails or a paycheque stops. Choosing between them is mostly a question of liquidity, not return. This guide is part of our mortgage payments hub.
Why a prepayment isn’t a safety net
A prepayment becomes home equity. Getting it back means borrowing against the home or selling it:
- It doesn’t lower your regular payment. A prepayment shortens the time left on the mortgage, but the same payment is still due next month. In a tight month, the money already prepaid doesn’t help unless your lender lets you skip or reduce a payment, which some contracts allow after prepaying. Check yours.
- Borrowing it back needs approval. A home equity line of credit or a refinance is a new credit decision based on your income and credit, which is hardest to get at the moment you’ve lost income. The HELOC guide explains how much you can borrow against a home.
- Breaking the mortgage to get at the equity can cost a penalty. Breaking a closed mortgage, paying it off early or prepaying more than your privileges allow usually costs the higher of 3 months' interest and the interest rate differential (IRD) on a fixed rate, and typically 3 months' interest on a variable rate; your mortgage contract sets the exact method and comparison rate, and a federally regulated lender must tell you how it calculates the penalty. The mortgage penalty guide shows how each method is worked out.
Cash in a savings account has none of these limits, which is why it usually comes before extra mortgage payments.
What a cash shortfall costs
Suppose a household had sent $8,000 to a mortgage at 4.5% instead of keeping it in savings, and then needs $8,000 for an emergency repair. With no cash, the repair goes on a credit card charging 20.99%.
- Interest the prepayment saves in a year: about $360
- Interest on the card if the balance stays for a year: about $1,679
The prepayment’s saving is wiped out several times over, and the household now carries the more expensive debt. Simple interest is used for both, to keep the comparison readable.
How card interest is charged, including the grace period and daily interest, is explained in how credit card interest works.
How big the fund should be
The usual guideline is several months of essential expenses, more for a single income, self-employment or commission pay, and more again for new homeowners facing their first repairs. The emergency fund guide shows how to work out your own number, and the emergency fund calculator does the arithmetic. For a homeowner, essential expenses include the mortgage payment, property tax, insurance and utilities; the homeowner carrying costs page lists each one.
Where to keep emergency money
The fund needs to be safe and quick to reach more than it needs a high return:
| Where | Access | Risk to the balance | Notes |
|---|---|---|---|
| High-interest savings account | Usually same day or next day | None at a CDIC member, within coverage limits | Rates change often; compare current rates |
| Savings held inside a TFSA | Same as a savings account | Same as above | Interest is tax-free; a withdrawal’s room comes back only the following year |
| Cashable GIC | Can be cashed early, usually with less interest | None, within coverage limits | Suits money you’re less likely to need soon |
| Non-cashable GIC | Locked until maturity | None, within coverage limits | Not suited to emergency money |
| Chequing account | Immediate | None, within coverage limits | Often earns little or nothing |
| Stocks or ETFs | Sale settles 1 business day after the trade (since May 27, 2024) | The price can be down when you need to sell | Better for long-term savings than for emergencies |
| Home equity line of credit | Immediate once approved | It’s a loan, not savings | Can be reduced or unavailable when you need it; a backup at best |
A sequence for building both
| Stage | Where extra cash goes |
|---|---|
| No cash cushion yet | Savings first, until a month or so of essential expenses is set aside |
| Building toward your target | Mostly savings, with some to the mortgage or other goals if you prefer to start both |
| Fund at its target | Extra mortgage payments, investing, or both |
| After using the fund | Back to rebuilding it before resuming extra payments |
High-interest debt such as a credit card balance usually comes before both, since paying it off saves more than either the savings account earns or the mortgage costs. If your income is uncertain, a larger fund buys time to keep up with payments; keeping your house after a job loss covers what to do if that happens.
Once the fund is in place
With the fund built, the question changes from safety to return: whether extra money does more on the mortgage or invested. That comparison, including a worked example and the order many people use for extra cash, is in paying down the mortgage vs investing. If you choose the mortgage, the mortgage calculator with extra payments shows what each extra amount saves, and your prepayment privileges set how much you can pay each year without a penalty.
Sources
The figures and rules on this page come from these sources, last checked against them between September 25, 2026 and September 29, 2026. How we check facts.
- BMO InvestorLine: T+1 (New Trade Settlement Date) FAQs
- cdic.ca: What's covered — CDIC
- Financial Consumer Agency of Canada: Breaking your mortgage contract
- Financial Consumer Agency of Canada: Mortgage fees: Prepayment penalties
- RBC: Variable Rate Mortgage | RBC Royal Bank of Canada