Collateral Charge Mortgage explained
With a standard-charge mortgage, the lender registers a charge for the exact amount you borrow, and the mortgage is tied to a specific loan with set terms. A collateral charge works differently: the lender can register the charge for an amount up to, or higher than, your home's value. This allows the mortgage to be re-advanceable, meaning you may be able to access more credit later, such as adding a line of credit, without paying to register a new charge.
The flexibility comes with a catch. Because the charge secures all debts you have with that lender, switching to a new lender at renewal usually requires discharging the collateral charge and registering a new mortgage elsewhere, which can involve legal and registration costs that a simple standard-charge transfer might avoid. Borrowers should weigh the re-advanceable convenience against the potential difficulty and cost of moving lenders later.