Unlike a standard mortgage, a collateral charge is re-advanceable. That means the lender can lend you more money after closing without you needing to refinance and pay a lawyer. You can keep re-using this charge, and a new charge will only be required if you want to borrow more than the amount that was originally registered. Most chartered banks offer both types of mortgages. A couple (TD Bank and Tangerine) only register their mortgages as collateral charges.
If you have a Home Equity Line of Credit, you have a collateral charge mortgage. A collateral charge can be used to secure multiple loans with your lender. This means credit cards, car loans, overdraft protection and personal lines of credit could also be included.
Pros and Cons of a Collateral Mortgage:

The PROS:
1) If you wish to borrow more money during the term of your mortgage, you can tap into your home equity without the expense of a mortgage refinance. You can save legal fees. (This is assuming of course, your personal credit and income are sufficient to qualify for more money.)
2) If you have a mortgage and a Home Equity Line of Credit (HELOC), it may be structured such that every time you make a mortgage payment, the amount you pay towards your principal balance is added to your HELOC limit. Large available credit, used wisely, is usually a good thing.
3) Collateral charges are often best suited to strong borrowers with lots of equity. They might readily access contingency funds at no cost down the road. This could be by increasing their mortgage loan amount or adding a home equity line of credit to the mix.
The CONS:
1) Some would argue you could be offered less competitive interest rates from your current lender at renewal than you will be from a new lender, as it can b more difficult to transfer the mortgage out as there are legal fees involved. This is slowly changing as the lenders are trying to fight for this business.
2) A collateral charge mortgage is not only a charge on your home, but can include other credit you have with that same lender. These lenders have a “right of offset,” meaning they can collect from the equity in your home on any financial products you have (or co-signed for) that are now in default.