Bidder numbers can be pre-assigned or assigned at check-in within any range you specify.
If you're uncertain which approach makes the most sense for your event, review this.
Bidder numbers are pre-assigned by default. Pre-assigned bidder numbers are issued as each ticket is created, according to the starting number specified (default = 300).
Once tickets and bidder numbers have been issued, editing existing pre-assigned bidder numbers requires Admin status (individual edits) and Chair status for bulk edits.
To edit Bidder Number settings:
Go to: Site Settings > Events > Gala Auction > Manage Bidder Numbers.
You can change the setting from pre-assigned to assign at check-in at any time (the changes will not be applied to any users that have already checked in).
You can also change the Minimum New Guest bidder number at any time, but the change will only be applied to future ticket sales.