Gross Debt Service Ratio (GDS)
It is one of the mathematical calculations used by lenders to determine a borrower's capacity to repay a mortgage. It takes into account the mortgage payments, property taxes, approximate heating costs, and 50% of any maintenance fees, and this sum is then divided by the gross income of the applicants.

Guarantor
A person with an established credit rating and sufficient earnings who guarantees to repay the loan for the borrower if the borrower does not.