Once a domain goes into Pending Auction status or is part of an active auction, your backorder/bid cannot be removed. For details on when a backorder can be removed, please see the article Changing or Deleting Bids on Backordered Domains.
Once the domain has been flagged to go into auction (Pending Auction), it may still appear on your backorder list for up to a few hours while the domains on our system are being queued for auction. During this transition period, the check box will be grayed out and you will no longer be able to change the bid or delete the domain. It is too late to be removed or make changes once in this status.
5.3. Backorder Cancellation. A backorder can be cancelled at any time before the posted backorder deadline, so long as the backorder is at the minimum bid.