To dismiss a challenge match invitation, you can click the red ‘X’ dismiss button on the match card in your To Do carousel.
This will take you to an overview of the challenge information and will ask if you are sure you wish to cancel the challenge invite. You can leave an optional comment, otherwise click the blue ‘Confirm Cancellation’ button. An email notification will be sent to your opponent confirming you have dismissed the challenge request.
NOTE: ladder position penalties may apply for cancelling a challenge request dependent on your competition administrators rules. In some instances (depending on the competition settings by the administrator), a warning message may display advising of the applicable ladder penalty.