Canada · Strategies · Tax-efficient debt

Cash damming

For the client with rental or business income and a home mortgage: reroute the plumbing. The business's expenses get paid from a dedicated credit line — whose interest is deductible — while the business's cash attacks the home mortgage. Same dollars, same total debt; but month by month, non-deductible mortgage becomes deductible borrowing, and the tax refunds start arriving.

The rerouting, plainly

Open a dedicated credit line — used for one thing only: paying the rental's or business's genuine operating expenses.
The revenue that used to pay those expenses goes against the home mortgage instead, as extra principal.
The line's interest is deductible (it funds income-earning expenses); the mortgage shrinks faster than its schedule; the refunds compound the effect.
When the mortgage is gone, what remains is the same debt the client always had — now fully deductible.

What it looks like in numbers

A worked file from the desk's verified model

8.75 yrs

to full conversion — versus 25 years on the normal schedule

$48,500

of tax refunds collected along the way

$12,400/yr

of ongoing tax savings once converted, every year after

Scenario: a $500,000 mortgage at 5% (25-year amortization) with $3,000/month of genuine rental or business expenses rerouted through a 6.5% line, at a 45% marginal rate. Net of the strategy's extra interest, the position at conversion is roughly $18,900 ahead — then the ongoing savings run indefinitely. Model any client's own numbers in the tool below.

The whole strategy is the paper trail. A dedicated line that pays only genuine income-earning expenses, never mingled with personal spending — that's what CRA's direct-use rule demands, and it's what the client's accountant must bless before the first dollar moves. Improvised versions of this strategy are how deductions get denied.

Who it serves best

Landlords with steady rental expenses; incorporated and unincorporated business owners with regular operating costs (see the BFS program — the same clients, and often the same file); and any client whose accountant has sighed about a big non-deductible mortgage while real business cash flow runs through their hands every month. The larger the monthly expense flow, the faster the conversion.

Questions advisors ask about it

How is this different from the Smith Manoeuvre?+

Same destination, different fuel. The Smith Manoeuvre converts through investing re-borrowed principal; cash damming converts through business cash flow — no new investment leverage, no market exposure added. For a client with real expense flow, damming is often the gentler entry; the two also combine.

Does it need a special mortgage?+

It needs a clean line beside the mortgage — a readvanceable structure like the Manulife One is the tidiest chassis, because sub-accounts keep the deductible line separated with the paper trail built in. Structuring that is the desk's half of the work.

Is there market risk?+

No new investment is made — the strategy only re-routes existing cash flows. The risks are execution risks: mixing personal spending into the line, expenses that aren't genuinely deductible, or rates moving (the line typically floats). All manageable; none ignorable.

What does CRA think of it?+

Interest on money borrowed to pay income-earning expenses is deductible under the ordinary direct-use rules — this isn't a loophole, it's plumbing. What CRA cares about is proof: the dedicated line, the clean flows, the documentation. Which is why the accountant signs off on the setup before it starts, not after.

From the desk

Anonymized case studies for this strategy are being prepared from real funded files — nothing invented, ever. The figures above come from the desk's verified model; run your client's own numbers and you'll see the working, not just the conclusion.

Model a file — the cash damming calculator The investing sibling — Smith Manoeuvre The chassis — Manulife One

If a client has rental or business expenses and a home mortgage, this conversation usually pays for itself within the first year's refund.

Arrange a confidential introduction

Ramin Hallaji, Principal — licensed in British Columbia (BCFSA) and Alberta, Dominion Lending Centres Group · 778-879-6768 · ramin@privatewealthfinancing.ca

Information, not tax or investment advice, and not an offer of financing. Deductibility depends on CRA's direct-use rules — genuine income-earning expenses, a dedicated facility, clean tracing — confirmed by the client's accountant before execution. Model figures assume constant rates and steady expenses; results vary by file. All lending subject to approval, verification, and property valuation. Private Wealth Financing arranges mortgage financing only.