Welcome to this thread, Dono D.
I appreciate you for voicing your interest in having the option to know if an estimate has already been viewed by your client. Though this is still unavailable, QuickBooks Online (QBO), is constantly changing and evolving based largely on the suggestions and requests of users like yourself.
In the meantime, I want you to get in the loop about the latest news and product developments in QuickBooks. That said, I encourage you to visit our Firm of the future site. To narrow down your search, you can go to the Product & Industry News tab.
You might also want to check out these articles for more tips on how to manage estimates including how to customize your estimates in QBO:
You can always find me here if you have follow-up questions about estimate features or other topics in QBO. Take care and stay safe.
