If you email a quote or estimate, your customer can accept or decline it themselves.
You'll receive a notification if the customer accepts. The status of the quote or estimate will update from pending to accepted.
You can then convert it into an invoice.
Cause
Resolution
Go to Sales, then select Quotes & estimates.
Select the quote or estimate you want to convert.
Select Create Invoice.
NOTE:
If the quote is still pending, select Accept and invoice.
Amend the details of the invoice if required.
Optionally, select Save as box and choose Draft or Pro Forma.
Select Save, Save & Email or Save & Print.
You've successfully converted the quote or estimate to an invoice. The status of the quote or estimate now shows as Invoiced. The invoice appears on your Sales Invoiceslist. Look on the Quotes & Estimates list to see the sales invoice number created from the quote or estimate.