What must be done before merging duplicate accounts in QuickBooks?

Before merging duplicate accounts in QuickBooks, it is essential to review and possibly back up your data. This step is crucial because merging accounts is a significant action that affects your financial records. If a mistake occurs during the merge—such as merging accounts that shouldn't be merged or losing important transaction history—a backup allows you to restore the original state of your data without any loss.

Creating a backup ensures that there is a fallback option available in case the results of the merge do not meet expectations or if errors are found post-merge. It provides peace of mind and helps maintain the integrity of your financial data, which is vital for accurate reporting and accounting.

Other actions, such as checking transaction histories or deleting accounts, do not provide the same level of protection against potential mistakes during the merging process. Therefore, backing up your data is the most comprehensive and protective measure to take beforehand.