shawfactor

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 <a href="http://lhero.org/plugins/lh-membership-numbers/" rel="nofollow ugc">LH Membership Number plugin</a>.
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 <a href="https://princesparktouch.com/" rel="nofollow ugc">princesparktouch.com</a> it is PPT). That prefix can make the number far more unique (globally).

LH Membership Numbers

yesim the plugin author but this plugin works perfectly as described (it is a very simple plugin so it is not for everyone).

Don't be f-wit like bgtbbox (the last reviewer), read what it does and if you don't think it works a specified put something in the support forum and I'll look at it.

Works perfectly

Plugin to allow users to login by a number, their user ID (optionally prefixed)

manu225

Create beautiful grids with flipping cards (image, text and link). Compatible with multisite. 
<a href="https://www.info-d-74.com/references/" rel="nofollow ugc">Here an example</a>
And there is a Pro version on my shop. <a href="https://www.info-d-74.com/en/flipping-cards-pro-plugin-wordpress-demos/" rel="nofollow ugc">See more here</a>

LH Membership Numbers vs Flipping Cards