Sharing additional details to your concern helps us align our understanding, Yo_Be_Low2. Currently, the option to add a Class to multiple transactions that don't have one at once is unavailable.

Nevertheless, we would love to hear your ideas about having this functionality in the program, and I suggest submitting feedback to our Product Development Team. Rest assured, they will review it and consider adding it for future updates.

You can follow the steps outlined by my colleague above to send your recommendation. You can also review our QuickBooks Feature Requests website for any updates on your request.

Moreover, this guide can give you information about organizing customer and vendor transactions within the program: Track hourly labor costs and profitability by project in QuickBooks Online.

We care about helping you in any way we can. If you have further questions about classes in QuickBooks or other inquiries, please don't hesitate to reach out. We're here to assist you at any time.