# Bidder Numbers
Auctria requires Bidders have a bidder# associated with them in order to place a bid.
# Linked Bidders
Multiple bidders can share a bidder#, in this case they are said to be linked. See Sharing Bidder Numbers for more details.
# Assigning Bidder#'s
The system will automatically assign bidder#'s when people buy tickets, or register, online based on the Bidder Registration/Checkout settings under the options of the Bidder Number Assignment panel.
- Always assign a bidder# when not specified
The default setting, the system will automatically generate a bidder# and assign it to the bidder when you add add a new bidder.
- Never automatically assign a bidder#
This will require bidders numbers be manually added at a later time, for example when you Check In Bidders, or by using the Renumber Bidders functionality.
- Only automatically assign bidder# on ticket sales
This will only assign a bidder number when a ticket is purchased. Online registration (only) will not assign a "bidder#"" and would need to be addressed in a similar fashion to the "Never automatically assign a bidder#" option.
In the case where you want to hand out bidder#'s when you Check In Bidders you can use the "Never assign" option above; or, you can set the system to assign a very high bidder# automatically using the "Next assigned bidder#" option setting.
Next assigned bidder#
This option setting can be found in the Bidder Number Assignment panel as well as in the Auction Details page under its SUMMARY tab in the "Advanced" panel.
If the value set in the Next assigned bidder# field is changed in one option panel, it will be updated in the other option panel to the same value.
# Using Very High Bidder Numbers
If all the auto-assigned bidder#'s are at, for example, 18000+ then you can easily reassign the numbers at check-in using the Check In Bidders page. You can also tell, at a glance, if bidders have checked-in by their assigned bidder number.
A related approach would be to renumber all bidders to very high bidder numbers using the Renumber Bidders function before the event and then change the numbers as bidders check-in at the event.