Hello and welcome to the QuickBooks Community, Bobbie22
We'll be happy to share some information on adding attachments to estimates in QuickBooks Online.
At the moment, the attachment would need to be added each time when creating an estimate through the + New button or from the Customer page (via New transaction).
As a workaround, you could use the Recurring transaction tool (available in QuickBooks Online Essentials, Plus, and Advanced).
This allows you to create a template for the estimate where the attachment can be uploaded. You can set the template to be Unscheduled (so that you use it as needed from the Recurring Transactions list, instead of being sent automatically).
Thanks for reaching Intuit QuickBooks for support on the Community. If you have any further questions, please post these below and we'll be happy to answer.
