Are you looking to reassigning bidder numbers at check in? Follow this process. 

Using the Butler> Bidder Lookup (check in / check out) type in the bidders first or last name, click on the black underlined portion of the name to view the details.

At the top of this page, there is a bidder number. You can change this bidder number by typing in the number you want. The system will check to see if that bidder number is available and change if so.

After adding all the correct information, phone number, email address, credit card information, click on the green COMPLETE Button in the top right corner. 

The bidder will then receive a Welcome text message. That message can be edited under Software Settings > Auction Settings > Butler Settings. Remember to use your shortcode [u] to include the bidding link.