I hear your sentiments, @Sarah-Zee. 

I can see the importance of having the option to combine multiple invoices for you and your business. 

Your feedback helps our Product Development team determine which feature will be implemented in the next future update. The change is also based on how popular a specific feature request is. Our product developers are continuously reviewing all customer's feature request. 

I also encourage you to visit this resource that will guide you in personalizing your sales forms: Customize invoices, estimates, and sales receipts in QuickBooks Online.

Thank you for your patience while we work on this feature update to merge multiple invoices. Please take care.