We'll create fresh WordPress site with LH Membership Numbers installed. You have 20 minutes to test the plugin after that site we'll be deleted.
Users of membership sites often have and use a membership number. Yet WordPress uses alpha numeric string for usernames for logging in. Why not use both by using the LH Membership Number plugin.
LH Membership Numbers allows a user to login by typing in their membership number. Their membership number is the unique user ID that every user is assigned in the database. Optionally administrators can assign a prefix to the membership number (eg for my sports league princesparktouch.com it is PPT). That prefix can make the number far more unique (globally).