Once a return is lodged it can only be deleted by ECQ representatives. In your Submissions Summary, click the Action box on the right of the return and select ‘Request to delete’.
A pop-up will appear asking you to provide a detailed reason why the deletion is required. Fill this in and click ‘Request to delete’. This will then be sent to ECQ representatives to review. While the request is being processed this return will show as 'Pending' status.