Currently, we are not able to restrict access. However, if we do not include you in our featured auction list only people that know your direct URL would theoretically be able to access your auction. Further, it is highly likely that only bidders that are familiar with your organization will actually bid on your items (particularly, if it is a school). Further, you are always able to delete bids from outside at any time. In addition, we recommend that you mention your restrictions on your website. Either on your homepage and/or under additional information for each item. General Setup > Default Auction Preferences > Additional Information.  Here is some recommended wording: Bidding is only allowed for supporters that are associated with our organization. We reserve the right to delete bids from supporters that are not part of our community.