XIRR Sensitivity Analysis is the analysis of how changes in timing or amount of cash flows affect the extended internal rate of return. It is relevant for structured repayments, investments, or yield evaluation. In underwriting, it provides business and banking context that supports facility structuring, risk assessment and credit-decision documentation. It helps convert raw borrower information into a clear credit narrative, especially when the relationship involves multiple facilities, lenders or business activities. For example, XIRR helps compare the true yield when cash flows occur on irregular dates rather than in equal monthly instalments. It matters because the same borrower can look different depending on banking arrangement, transaction behaviour, documentation quality and business context. The common caution is to document the source, date, assumptions and credit impact so the term does not become a vague narrative label.