Thanks for posting your question here in the Intuit Community, user81000,
Let me get the help you need in reclassifying your transactions.
Currently, able to reclassify transactions by batch is not an option for QuickBooks Online user. This specific feature is available in QuickBooks Online Accountant account.
In your case, to help us reclassify your transactions by batch, I'd recommend contacting your accountant.
To know more on how this feature works, here's a great resource that you can check: How to use the reclassify transactions tool in QuickBooks Online Accountant.
If there's anything else you need help with in managing your transactions, please let me know. I'm always here to help. Have a great day!