What a HELOC actually is
A Home Equity Line of Credit (HELOC) is a revolving line of credit secured against the equity in your home. Unlike a mortgage — which gives you a fixed lump sum with fixed scheduled payments — a HELOC works more like a credit card against your property: you get a credit limit, borrow what you need, repay it, and borrow again. You only pay interest on the amount you have drawn, not the full limit.
The core advantage is flexibility. You don't need to know upfront exactly how much you'll spend or when. For a renovation that takes 18 months and has unpredictable costs, a HELOC lets you draw in stages. For an emergency buffer you hope never to use, a HELOC costs you nothing while it sits at zero.
How much can you borrow? The two limits that matter
Two rules from OSFI (Canada's banking regulator) cap how much you can borrow against your home. Both apply simultaneously, and the lower result is your actual limit.
Rule 1 — The 65% revolving cap
The HELOC itself (the revolving portion) cannot exceed 65% of your home's appraised value. This is a hard regulatory ceiling — no federally regulated lender can go above it.
Rule 2 — The 80% combined cap
Your total secured borrowing against the property — mortgage balance plus HELOC combined — cannot exceed 80% of your home's value. This is the same limit as the standard high-ratio mortgage cutoff.
65% of $900,000 = $585,000 − $400,000 mortgage = $185,000 HELOC room
80% of $900,000 = $720,000 − $400,000 mortgage = $320,000 combined room
You are limited by the lower figure: $185,000 available.
This is where most people get confused. The 65% rule binds first in most cases because it creates a lower ceiling than the 80% rule once you factor out the existing mortgage.
Why the 65% rule usually binds first
If your mortgage balance is large relative to your home value, the 80% rule may actually bind first — especially if you've recently purchased with a small down payment. But for most homeowners who have been paying down their mortgage for years, the 65% revolving cap is the constraint. The calculator above shows which limit applies in your situation.
HELOC vs. refinance vs. second mortgage — which one fits
These three options all let you access your home equity, but they work very differently. The right answer depends on how much you need, whether you need it all at once, and what your existing mortgage looks like.
Home Equity Line of Credit
- Revolving — borrow, repay, borrow again
- Interest-only minimum payments
- Variable rate (Prime + spread)
- No prepayment penalty to access funds
- Capped at 65% LTV (revolving)
- Requires qualification at stress-test rate
Mortgage Refinance
- Replaces your mortgage entirely
- Lump-sum payout at closing
- Fixed or variable rate option
- May trigger prepayment penalty on existing mortgage
- Can access up to 80% LTV
- Usually lower rate than a HELOC
Second Mortgage
- Separate loan behind your first mortgage
- Fixed term and payments
- Higher rate than first mortgage or HELOC
- No penalty on your first mortgage
- Used when HELOC/refinance is not available
- Often from private or B-lenders
What a HELOC actually costs
Understanding the rate structure matters because HELOC pricing is fundamentally different from a mortgage.
Variable rate — it moves with Bank of Canada decisions
HELOC rates are variable, typically set at the lender's prime rate plus a spread. When the Bank of Canada raises or cuts its overnight rate, prime rate follows — usually within days — and your HELOC rate moves with it. There is no fixed-rate lock on a standard HELOC. Some lenders offer a "fixed segment" option where you can convert part of your balance to a fixed term, but the revolving portion remains variable.
Interest-only minimums — the double-edged feature
Your required minimum payment on a HELOC is typically interest only on the drawn balance. This keeps your carrying cost low in any given month, but it means your principal never shrinks unless you deliberately pay it down. A HELOC balance carried at interest-only for years costs far more in total interest than a conventional mortgage with a fixed amortization schedule.
A HELOC rate is almost always higher than a first mortgage rate, but lower than a credit card or unsecured line of credit. The secured nature of the debt — your home as collateral — is what earns the lower rate relative to unsecured products.
Readvanceable mortgages — the version most people don't know about
A readvanceable mortgage combines your mortgage and a HELOC into one registered product. The key feature: as you make your regular mortgage payments and pay down principal, the HELOC limit automatically increases by the same amount. You never have to re-qualify to access that new room.
Most major Canadian lenders offer a version under different brand names (CIBC's All-In-One, TD's FlexLine, Scotiabank's STEP, National Bank's All-In-One, BMO's ReadiLine, and so on). The structure varies slightly, but the core mechanic is the same.
Who readvanceable mortgages work best for
If you have ongoing borrowing needs — such as business cash flow, investment property purchases, or multi-phase renovations — a readvanceable structure means you don't need to keep going back to your lender for a new loan. Each dollar of mortgage principal you repay becomes immediately available equity to draw on again.
Worth asking about at renewal if you anticipate needing flexible access to equity over the next 5–10 years. Once your mortgage is registered as a conventional charge (not a collateral charge), moving to a readvanceable product typically requires a refinance and new registration — so this is a decision worth making proactively.
The honest risks — do not skip this
A HELOC is one of the most flexible financial tools a homeowner can access. It is also one of the easier ways to accumulate debt that feels manageable right up until it isn't. These risks are real.
- Your home is the collateral This is secured debt. Default on a HELOC the same as on a mortgage — the lender's remedy is the same. The low interest rate reflects the collateral, not a reduced consequence for non-payment.
- Variable rate means payment uncertainty If rates rise 2% and you're carrying a $200,000 HELOC balance, your annual interest cost rises by $4,000. Budget stress-test your own situation before drawing heavily.
- Interest-only payments make balances sticky You can legally make only the interest payment every month forever. Many borrowers do exactly this, watching a HELOC balance stay flat for years while paying thousands in interest. This requires deliberate discipline to avoid.
- Lenders can reduce or freeze a HELOC If your home's value drops significantly, or your financial situation changes materially, a lender can reduce your available limit or freeze draws. This is rare but has happened during severe market downturns. A HELOC is not a guaranteed emergency fund.
- The flexibility is the risk The same feature that makes a HELOC useful — borrow whenever, repay whenever — makes it easy to over-borrow without a specific repayment plan. A HELOC is a powerful tool for people with a plan, and an expensive habit for people without one.
Common uses — and one that self-employed borrowers should know
- Home renovations — the most common use. Ideal because costs are unpredictable, timelines stretch, and the renovation may increase the property value that backs the HELOC.
- Debt consolidation — moving high-rate credit card or personal loan debt into a HELOC at a lower rate reduces your carrying cost, but requires discipline not to re-accumulate the original debts.
- Investment property down payment — using equity in your principal residence to fund a rental property purchase. The interest on the HELOC portion used to earn investment income may be tax-deductible (confirm with your accountant).
- Business cash flow — particularly relevant for self-employed borrowers who may have irregular income timing. A HELOC can bridge gaps between receivables without expensive business financing. Interest may be deductible if used for business purposes.
- Emergency buffer — keeping a HELOC open at zero balance costs you nothing (or a small annual fee depending on lender) and provides a substantial safety net that most savings accounts cannot match in size.
- Education costs — tuition and living expenses paid in instalments over years, rather than needing the full amount financed upfront.