During the Submission phase the customer may decide to cancel the contest if the chances of receiving a quality submission are low based on the list of the registrants and the forum activity.
A contest can only be canceled during the Submission phase if there has not been a submission yet and if there's still more than 24 hours before the Submission deadline. When canceling a contest an announcement should be posted on the forum and the status of the contest should be set to "Cancelled - Client Request".

For more details about managing competitions, please refer here.