Let’s start by going to cases,
Find the case where the Land Registry application needs to be cancelled,
Go to the post completion milestone,
Click on the EDRS button,
Click on view or the submission ID next to the pending application,
Next to each of the pending documents press cancel,
You may get a pop up warning you that you are submitting a cancellation letter to the Land Registry. If this happens press ok. Once this is done, the Land Registry will be notified that the application has been cancelled.