Hello there, Ginfinch2611. QuickBooks does not currently send an automated email to you when a customer accepts an estimate; only the customer receives the confirmation email.
However, you can verify the status of an estimate directly within your QuickBooks Online account by going to the All Apps menu > Sales & Get Paid > Sales Transaction. Then, locate the estimate and check the Status column. If an estimate is marked as "Accepted," it means your customer has approved it.
When you're ready to bill your customer, you can convert the estimate to an invoice so you don't have to enter the information twice.
If you have further questions, please feel free to ask. We're here to help.
