The short answer is no. Think of it this way: you wouldn’t want something to be accepted, then you start the project or fulfilling the order and then find that the estimate has been unaccepted.
With that being said, if you really need to unaccept an estimate, here’s what you can do:
Go to Estimates
Check the box beside the estimate
Click the grey ‘Copy’ button located above the list of estimates
4. Save/send the copy of the estimate
5. Back on the main list of estimates, check the box beside the
6. Click the grey ‘Delete’ button located above the list of estimates
If you’d like to reuse the estimate number, you will first need to edit the original estimate, change the estimate number, save then delete the estimate. You can then edit the new estimate and put in the old estimate number.