Which ratio should typically not exceed 36% when qualifying for a mortgage?

When qualifying for a mortgage, the back-end ratio is crucial because it represents the total percentage of a borrower’s gross monthly income that goes toward all of their monthly debts, including mortgage payments, property taxes, insurance, and any other loans or credit obligations. A back-end ratio that typically should not exceed 36% reflects sound lending practices, as it allows lenders to ensure that borrowers are not overextending themselves financially. By keeping this ratio below 36%, lenders can assess a borrower's ability to manage additional expenses related to homeownership beyond just the mortgage payment.

This ratio is a fundamental part of the underwriting process, as it helps in determining the risk associated with lending to a particular borrower. If the back-end ratio is too high, it suggests that a borrower may struggle to meet their financial obligations, increasing the risk of default. Therefore, maintaining this ratio at or below 36% helps lenders mitigate risk while supporting borrowers in achieving sustainable homeownership.