The donor portal login must match the first name, last name, and primary email address for the constituent in order to link to an existing constituent record.

If a constituent creates a donor portal account using a different email or name than the one that is already in the database, a new constituent record will be created that is tied to that portal account.  The bidder will be able to do their online bidding, but you may need to take special care at checkout if they used another bidder ID for a paddle raise or other add-on item.