Flexible mortgage products give you more than a standard mortgage — they combine borrowing, revolving credit, and sometimes banking into a single structure. Here is how they work and whether they are right for you.
Types of flexible mortgages
| Product Type | How It Works | Key Feature |
|---|---|---|
| Readvanceable mortgage | Mortgage + HELOC under one registered charge. HELOC limit grows as mortgage principal is repaid | Access equity without refinancing |
| All-in-one account | Mortgage + chequing + savings in a single account. Interest calculated daily on net balance | Every dollar reduces interest |
| Hybrid / split mortgage | Multiple mortgage sub-accounts (segments) with different rates and terms under one product | Mix fixed and variable rates |
| HELOC-only mortgage | Entire mortgage is structured as a HELOC (interest-only option) | Maximum flexibility, no forced principal repayment |
How a readvanceable mortgage works
A readvanceable mortgage is registered as a collateral charge (not a standard charge) for the maximum lending value — typically 80% of your home’s value. This single registration covers both your mortgage and HELOC.
Example: $600,000 home, $480,000 total credit (80% LTV)
| Component | Day 1 | After 2 Years | After 10 Years |
|---|---|---|---|
| Mortgage balance | $480,000 | $440,000 | $320,000 |
| HELOC available | $0 | $40,000 | $160,000 |
| Total credit | $480,000 | $480,000 | $480,000 |
As you pay down the mortgage, your HELOC limit automatically increases by the same amount. You can access this credit at any time for any purpose — renovations, investing, emergencies — without applying for a new loan or paying legal fees.
Major flexible mortgage products compared
| Product | Lender | Readvanceable | Sub-Accounts | All-in-One Banking | Rate Premium |
|---|---|---|---|---|---|
| Scotia STEP | Scotiabank | Yes | Up to 3 sub-accounts (fixed/variable) + HELOC | No | ~0.10–0.15% |
| Manulife One | Manulife Bank | Yes | Multiple sub-accounts | Yes — chequing, savings, mortgage combined | ~0.15–0.30% |
| National Bank All-in-One | National Bank | Yes | Up to 4 sub-accounts + HELOC | Yes | ~0.10–0.20% |
| TD FlexLine | TD | Yes | Multiple segments + HELOC | No | ~0.10–0.15% |
| RBC Homeline Plan | RBC | Yes | Mortgage + HELOC segments | No | ~0.10–0.15% |
| BMO ReadiLine | BMO | Yes | Mortgage + HELOC | No | ~0.10% |
The Smith Manoeuvre connection
The most financially powerful use of a readvanceable mortgage is the Smith Manoeuvre — a strategy to make your mortgage interest tax-deductible:
How it works
- Make your regular mortgage payment (which includes principal repayment)
- Your HELOC limit automatically increases by the principal portion
- Borrow from the HELOC and invest in an income-producing portfolio (Canadian dividend stocks, ETFs)
- The interest on the HELOC becomes tax-deductible because the borrowed funds are used for investment
- Use investment income (dividends) to make additional mortgage prepayment privilegess
- Repeat — over time, your non-deductible mortgage debt is replaced with deductible investment debt
Smith Manoeuvre requirements
| Requirement | Why |
|---|---|
| Readvanceable mortgage | HELOC must automatically increase as mortgage is paid down |
| Non-registered investment account | Invested funds cannot go into RRSP, TFSA, or other registered accounts |
| Income-producing investments | Interest is only deductible if the investment has a reasonable expectation of generating income |
| Separate HELOC tracking | Keep the investment HELOC completely separate from any personal-use HELOC borrowing |
| Long time horizon | The strategy works best over 15+ years with consistent execution |
All-in-one accounts: Manulife One deep dive
The Manulife One is the most well-known all-in-one product. It works differently from a standard mortgage:
How daily interest calculation works
| Day | Balance Start | Paycheque In | Expenses Out | Closing Balance | Interest Charged |
|---|---|---|---|---|---|
| 1st (payday) | $400,000 | −$5,000 | — | $395,000 | $395,000 × daily rate |
| 5th | $395,000 | — | +$200 (groceries) | $395,200 | $395,200 × daily rate |
| 10th | $395,200 | — | +$1,500 (rent/bills) | $396,700 | $396,700 × daily rate |
| 15th (payday) | $396,700 | −$5,000 | — | $391,700 | $391,700 × daily rate |
Because interest is calculated daily on the net balance, every dollar deposited — even temporarily — reduces your interest. If your paycheque sits in the account for 14 days before bills come out, you save interest on that $5,000 for 14 days.
Who benefits most from Manulife One
| Profile | Benefit Level | Why |
|---|---|---|
| High-income earner | High | Large paycheques reduce balance significantly between spending |
| Irregular income (self-employed) | High | Large deposits offset periods of lower income automatically |
| Two-income household | High | Two paycheques keep balance lower more often |
| Living paycheque to paycheque | Low | No surplus cash to reduce interest — the rate premium just costs more |
| Heavy credit card user | Moderate | If you pay off cards monthly, keeping cash in Manulife One longer saves interest |
Hybrid / split mortgage strategy
Many flexible mortgage products allow you to split your mortgage into multiple sub-accounts with different rates and terms. This is useful for diversifying rate risk:
Example: $500,000 split mortgage
| Segment | Amount | Type | Rate | Term |
|---|---|---|---|---|
| Segment 1 | $250,000 | 5-year fixed | 4.49% | 5 years |
| Segment 2 | $150,000 | Variable (ARM) | 4.20% | 5 years |
| Segment 3 | $100,000 | HELOC (interest-only) | 6.45% | Revolving |
This gives you the stability of a fixed rate on half your mortgage, the potential savings of a variable rate on another portion, and flexible access to equity through the HELOC.
Collateral charge vs standard charge
Flexible mortgages are registered as collateral charges, which has important implications:
| Feature | Standard Charge | Collateral Charge |
|---|---|---|
| Registered amount | Exact mortgage amount | Up to 125% of home value |
| Re-borrow as you pay down | No — requires refinance | Yes — automatic with readvanceable |
| Switch lenders at renewal | Simple transfer (no legal fees) | May require discharge and re-register (legal fees of $500–$1,000+) |
| Additional borrowing | New application and registration | May be available within existing registration |
| HELOC included | Separate registration needed | Included under same charge |
The main drawback of a collateral charge is that switching lenders at renewal is more expensive and complicated. You may need to pay legal fees to discharge the collateral charge and register a new one with the new lender.
When a flexible mortgage is worth it
| Situation | Flexible Mortgage | Standard Mortgage |
|---|---|---|
| Planning the Smith Manoeuvre | ✓ Essential | ✗ Cannot readvance |
| Want HELOC access as equity grows | ✓ Automatic | ✗ Needs refinance |
| Two-income household with surplus cash | ✓ All-in-one saves interest | ✗ No daily interest benefit |
| Plan to stay with same lender long-term | ✓ No switching penalty concern | Either works |
| Want the lowest possible rate | ✗ Rate premium | ✓ Best rates |
| Plan to switch lenders at renewal | ✗ Collateral charge switching costs | ✓ Easy transfer |
| Simple needs — just a basic mortgage | ✗ Unnecessary complexity | ✓ Keep it simple |
The bottom line
Flexible mortgages are powerful tools for borrowers who will actively use the features — especially the readvanceable capability for the Smith Manoeuvre or the all-in-one structure for high-income households. But they come with a rate premium and collateral charge complications that make switching lenders harder. If you want the lowest rate and plan to shop lenders at every renewal, a standard mortgage with a standard charge is the better choice.