Felix Serial Number Warranty and License For WooCommerce lets you assign a unique serial number to each unit of a WooCommerce product — automatically at checkout, or by hand from a pre-generated pool — and gives you a dedicated admin screen to search, filter, and manage every serial number you’ve ever issued.

Free features:

Enable serial numbers per product (Simple and Variable products supported).
One serial number per ordered unit, assigned automatically at checkout.
Auto-generate serial numbers using a configurable prefix, suffix, length, and character set — or paste in your own pre-made list.
A searchable, filterable (by product or status) admin list of every serial number, with add/edit/delete.
Manually add or override a serial number on the order edit screen — useful for orders placed before a product had serial numbers enabled.
Serial numbers are always visible to the admin on the order edit screen, and optionally shown to customers in order emails and their My Account order view.
A serial number that’s never been used is automatically released back to the pool if its order is cancelled or refunded.

Pro features (sold separately): license key activation with configurable triggers (immediate, on order completion, customer self-activation, or your own external system via a REST API), license renewals, warranty tracking with warranty extensions, per-product custom auto-generation rules, keeping WooCommerce stock in sync with your serial number pool, bulk generation, CSV import/export, printable order slips, manually resending a serial/license/warranty notification email, and outbound webhooks for your own integrations.