Hi christopherjhoh,

Having the option to change a class on multiple transactions in QuickBooks Online (QBO) would be beneficial to your business. I'll take note of your suggestion and submit it directly to our product developers. 

From there, they'll be able to review and may implement this in the future updates.

Know that we are constantly improving our product's feature to meet your needs. Everything we have developed within the program derives from listening to our customers.

As always, you can check regularly for product updates and feature enhancement through this link: QuickBooks Blog.

Though, you can reach out to accountant for help reclassifying multiple transactions, since they have the Reclassify tool as mentioned by vpcontroller.

If you have any follow-ups or other concerns, please leave a comment below. I'm here to help. Have a great day.