Welcome to the Community, @humble226.

The option of deleting multiple transactions in the register isn't available in QuickBooks Online (QBO) yet. You'll have to delete transactions one at a time.

I want to ensure that customers like you are having the best possible experience while working with QuickBooks. If you think this option is what you need for your business, you may submit your feedback/product suggestions straight to our product engineers for future update.

To submit your suggestions, go to the Gear icon, select Feedback, share your feedback or suggestions under the Feedback page, click Next, and send your message.

We value your feedback and want your voice to be heard by addressing all concerns. Feel free to add a comment or drop a post if you have further concerns. We're always here to help you out. Wishing you continued success!