Sole Banking is the arrangement where the borrower banks exclusively with one lender for credit facilities. It gives better account visibility and control. It may reduce information gaps compared with multiple banking. 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, sole banking gives clearer visibility of credits and debits, while multiple banking may require external exposure confirmation. 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.