Investor Encyclopedia

GDS/TDS

GDS/TDS: a practical Canadian real estate investor guide to definition, deal math, underwriting use, common traps, and Realist.ca implementation.

Definition

Gross debt service and total debt service are borrower qualification ratios used in Canadian mortgage underwriting. GDS looks at housing costs versus gross income; TDS adds other debts.

Formula

GDS = housing costs / gross income. TDS = housing costs plus other debt payments / gross income.

Example

In underwriting, tag GDS/TDS beside the exact source input and rerun the model when that input changes. The point is not a pretty metric; it is a better buy, hold, refinance, or walk decision.

Why It Matters

GDS/TDS changes what a disciplined buyer can pay, how much debt the asset can safely carry, and whether the return is coming from operations or fragile assumptions.

Investor Interpretation

Use it to kill bad deals quickly. If the back-of-envelope version does not survive conservative assumptions, do not spend five hours making it look alive.

Realist Tie-In

Realist.ca can make GDS/TDS searchable as an encyclopedia entry, link it to property underwriting, and show it beside listings, saved analyses, market pages, and investor lead magnets.