What Is a Second Mortgage?

If you've built up equity in your home, a second mortgage is one way to tap it without touching your existing first mortgage. It can fund a renovation, consolidate debt, or cover a major expense — but it sits behind your first mortgage in priority, which shapes both the rate and the risk. Here's what you need to know.

Key takeaways

• A second mortgage is a loan secured against your home, on top of your existing first mortgage.
• Because it ranks behind the first mortgage, lenders take on more risk — so rates are typically higher.
• A HELOC is a common, flexible form of borrowing against equity alongside your first mortgage.
• Your equity is your home's value minus what you still owe — that's the pool a second mortgage draws from.
• It's secured by your home, so missed payments put the property at risk.

How a second mortgage works

A second mortgage is an additional loan registered against your property while your first mortgage stays in place. The word "second" refers to priority: if the home is ever sold or foreclosed, the first mortgage is repaid before the second. That extra risk for the lender is why second mortgages usually carry higher rates than firsts.

It draws on your home equity — the difference between your home's market value and the balance left on your first mortgage. The more equity you've built (through payments and appreciation), the more a lender may let you borrow.

Understanding your equity

Equity is the foundation of any second mortgage. As you pay down your first mortgage and as your home's value changes, your equity grows. Here's the simple picture:

Paying down your first builds the pool

Every prepayment on your first mortgage grows your equity. See how to pay off your mortgage faster and prepayment privileges.

Second mortgage vs HELOC

People often lump these together, but they differ. A traditional second mortgage advances a lump sum with set payments. A HELOC (home equity line of credit) is revolving credit you draw on as needed and repay flexibly. Both are secured by your home and both sit behind your first mortgage.

For a deeper look at the line-of-credit option, read what is a HELOC.

The risks and when it makes sense

A second mortgage can be a smart tool — or an expensive trap. Because it's secured against your home, falling behind on payments can ultimately put the property at risk. And the higher rate means borrowing isn't cheap.

Your home is on the line

A second mortgage is debt secured by your house. Borrow only against a clear plan to repay, and weigh whether refinancing your first mortgage might be cheaper overall — see should I refinance my mortgage.

• Often makes sense: consolidating higher-interest debt, a value-adding renovation, or a clear short-term need.
• Approach with caution: covering ongoing shortfalls, lifestyle spending, or anything without a repayment plan.
• Compare alternatives: refinancing the first mortgage, or a HELOC, may cost less.

A smarter way to build equity faster

The more equity you hold, the more options you have — including better terms on any second mortgage. One of the quickest ways to build equity is to spend less acquiring the home in the first place.

Keep more equity from day one

Eligible HOMEH buyers receive the industry's highest Cashback Rebate — money that stays in your pocket and strengthens your equity position. Sellers list for 1%, or free when they also buy with HOMEH within 6 months, or $395 + HST with a Mere Posting. Explore your numbers with the mortgage calculator or start at get a mortgage.

To understand the foundations, read the pillar guide how mortgages work in Canada.