# Debt Serviceability Metrics and Qualifying Rates: Strategic Bridges for Approval

> GDS/TDS calculations for self-employed borrowers adjust income differently:.

Category: Financing
Last verified: 2026-02-18
Source: https://ratellow.com/faqs/financing/debt-serviceability-metrics-and-qualifying-rates-strategic-bridges-for-approval

## Answer
| Income Type | How Lenders Calculate It |
|---|---|
| **Sole proprietor** | Line 15000 (net business income) from T1 |
| **Incorporated** | T4 salary + eligible dividends (may gross-up) |
| **Commission** | 2-year average of T4/T4A income |
| **Rental income** | 50-80% of gross rent as offset |
| **Non-recurring income** | Generally excluded from qualification |

Many self-employed borrowers under-report income for tax purposes — this creates a qualifying gap that BFS programs address.

## Related guide
- https://ratellow.com/guides/self-employed-mortgage-bfs

## Sources
- Guarantors and co-signors of mortgages — https://www.osfi-bsif.gc.ca/en/guidance/guidance-library/residential-mortgage-underwriting-practices-procedures-guideline-2017#2.3.2
- Contents — https://www.sagen.ca/ups/underwriting-documentation/#documentation
- I. Purpose and scope of the guideline — https://www.osfi-bsif.gc.ca/en/guidance/guidance-library/residential-mortgage-underwriting-practices-procedures-guideline-2017#1.0