Second mortgage or refinance: the real question is what it costs to touch the first one.

A refinance replaces the first mortgage entirely. If the client is mid-term, that usually means breaking the existing contract, which can trigger a prepayment penalty — the greater of three months' interest or the interest rate differential. The new mortgage is registered fresh, and total secured debt is capped at 80% of the home's appraised value.

That cap matters most for a client sitting on a rate well under today's market: breaking it to refinance means giving it up entirely, not just paying a penalty on the amount being pulled out. Every dollar of the new, larger mortgage is priced at whatever rate is available today, not the rate the client originally signed at — which is easy for a client to overlook when they're focused only on the equity they want to access.

There are also new registration and administrative costs with a refinance that a second mortgage simply doesn't trigger — a fresh appraisal in most cases, new legal fees to discharge the old charge and register the new one, and potentially a new mortgage loan insurance premium if the loan amount increases or the amortization extends.

A second mortgage is a separate loan registered behind the first mortgage as its own charge on the property. The first mortgage isn't touched — same rate, same term, same payments continuing exactly as before. The second mortgage is a distinct loan with its own payment, typically capped at 80% of the home's appraised value minus the existing mortgage balance.

It's worth noting a second mortgage and a HELOC aren't mutually exclusive with each other, but a client generally can't stack a second mortgage on top of an existing HELOC and a first mortgage without the combined total still respecting the same 80% overall ceiling — the math has to work across every charge registered against the property, not just the newest one.

Second mortgages sit in a riskier repayment position: if a property is ever sold in default, the first mortgage is paid out before anything reaches the second lender. That risk gets priced into the rate, which is why a second mortgage is generally more expensive than the same client's first mortgage or a HELOC. Fee ranges and specific rates vary meaningfully by lender and by file — confirm current pricing per deal rather than quoting a flat number to a client.

Many second mortgages come from lenders outside the major banks — mortgage investment corporations, credit unions, or private lenders — because a first-position lender is often unwilling to sit behind another charge on the same property. That widens the range of possible terms and costs considerably, which is exactly why getting an actual quote for the specific file matters more than working from a general rule of thumb.

For files with less conventional income documentation, this is often where outsourced underwriting support earns its keep — packaging a second-mortgage file so it moves quickly with a lender who isn't the client's existing bank.

1. 01Get the exact prepayment penalty quote to break the first mortgage — the greater of three months' interest or the interest rate differential.
2. 02Get a real rate and fee quote for a second mortgage sized to the amount the client actually needs.
3. 03Compare total cost over the period the client expects to hold the property, not just the headline rate on either option.

Both paths need clean documentation moved fast — appraisal, title, existing mortgage statement, and income verification. That's operational work, not advisory work, and it's exactly what Treadstone's fulfillment and underwriting support is built to absorb, so a broker can spend the conversation on which option actually fits instead of chasing paperwork.

It's also worth running both quotes in parallel rather than sequentially wherever possible — a prepayment penalty quote from the first lender and a rate quote for a second mortgage from a couple of panel lenders. A client comparing two real numbers side by side makes a faster, better-informed decision than one weighing a real quote against a rough estimate for the option not yet priced out.