We use access codes that are given to each registrant type. These codes modify the online pricing structure appropriately. A different staff member is responsible for each class of complimentary registrants. They automatically receive an e-mail stating that someone has used their registration number. An example of this would be the speaker liaison.
Some conferences have a companion program or golf tournament.
In such cases, we allow multiple credit card payments in the same transaction. Many times, for example, our members use a corporate card for the main registration and a personal card for the golf tournament. We don't have the data from online registrations automatically entered into our master database. This additional step may appear somewhat backwards, but it helps us maintain the integrity our data. We have, what I would consider, extremely high data standards.