The requirement to retain transaction details for joint accounts is rooted in ensuring transparency and accountability in financial operations. Transaction details provide a comprehensive record of all activities that have taken place on the account, including deposits, withdrawals, and any other transactions. This documentation is crucial for proper record-keeping and aids in resolving any disputes that may arise, as well as ensuring compliance with legal and regulatory standards.
Maintaining transaction records supports various regulatory needs, such as audits and investigations, by providing a clear and verifiable history of account activity. This practice not only bolsters the integrity of the financial institution but also protects the interests of all account holders involved.
While the other options may seem relevant, they do not encompass the specific requirement for joint accounts as comprehensively as transaction details do. Sales agreements, identification documents, and all business communications serve different purposes and may not meet the necessary criteria for ongoing account management and regulatory compliance.