Data loss is a major concern when switching from Desktop to Online. To prevent it, always back up your company file before migration. Clean up old transactions, reconcile accounts, and finalize open invoices. Use QuickBooks’ official conversion tool to transfer data. After the process, cross-check customer balances, inventory, and payroll settings. QuickBooks Online offers secure cloud storage, remote access, and automatic updates. Careful planning and verification make the migration safe and efficient, ensuring all historical financial data remains intact for accurate reporting.