Hi there, @MMV,

Thanks for joining the discussion. I appreciate you for putting your voice out and sharing your feedback here in our forums.

I completely understand the situation. Being able to update the products/services and retaining the Description on your invoice line items would be a handy feature in QuickBooks Online. This preference, however, is unavailable at the moment. As a workaround, you can follow @Malcolm Ziman's suggestion to create another line for the new item then copy and paste the description from the previous product.

I already took note of your request and will update you once this information is available for our users.

If you have any other questions, please let me know, and I'll be happy to help. Thanks again for visiting our forum today, have a great and productive week!