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)

Automattic

WooCommerce

Manos (a11n)

SomewhereWarm

Chris Lilitsas (a11n)

Free add-on for the official <a href="https://woocommerce.com/products/gift-cards/" rel="nofollow ugc">WooCommerce Gift Cards</a> extension that allows you to use the default coupon form to apply and redeem gift cards.
After activating the plugin, the “Have a Gift Card?” form will be hidden, and customers will be able to apply gift card codes using the coupon input field.
Note: This plugin has been created to validate and refine a feature that may be rolled into WooCommerce Gift Cards — or dropped! — in the future.
Important: This plugin is not compatible with the Cart and Checkout Blocks.
Important: The code in this plugin is provided “as is”. Support via the WordPress.org forum is provided on a voluntary basis only. If you have an active subscription for WooCommerce Gift Cards, please be aware that WooCommerce Support may not be able to assist you with this experimental plugin.

Gift Cards – Coupon Input

Free mini-extension for WooCommerce Gift Cards that allows you to use the default coupon form to apply and redeem gift cards.

LH Membership Numbers vs Gift Cards – Coupon Input