With WooCommerce Maximum Products per User module you can set how many products can user buy. Products bought are calculated by lifetime stats (i.e. not per order). Please note, that there is no maximum quantity set for not-logged (i.e. guest) users. Product quantities are updated, when order status is changed to completed.

All Products

WooCommerce Maximum Products per User - Admin Settings - All Products Options

Enable section
Enables/disables "All Products" section.__ALG_REMOVE__
Default: no
Maximum Allowed Each Product's Quantity per User
This will set maximum quantity for each product globally.__ALG_REMOVE__
Default: 1

Per Product

WooCommerce Maximum Products per User - Admin Settings - Per Product Options

Enable section
This will add new meta box to each product's edit page. __ALG_REMOVE__
Default: no

After enabling “Per Product” checkbox, please open some product’s admin edit page. There you will find two new meta boxes (“Booster: Maximum Products per User” and “Booster: Maximum Products per User: Sales Data”). In first one you will be able to set maximum quantity for the current product. Second one will display current sales data:

WooCommerce Maximum Products per User - Admin Settings - Per Product - Meta boxes

General Options

WooCommerce Maximum Products per User - Admin Settings - General Options

Customer Message
Replaced values: %max_qty%, %product_title%, %qty_already_bought%, %remaining_qty%.__ALG_REMOVE__
You can only buy maximum %max_qty% pcs. of %product_title% (you already bought %qty_already_bought% pcs.).
Block Checkout Page
This will stop customer from accessing the checkout page on exceeded quantities. Customer will be redirected to the cart page.__ALG_REMOVE__
Default: no
Calculate Data
This will calculate data for older orders.
Accessible through:
  • WooCommerce > Settings > Booster > Shipping & Orders > Maximum Products per User
Tested on WooCommerce 4.6.2 and WordPress 5.5.3
Plugin can be downloaded here. If there are any locked fields in the module, you will need to get Booster Plus to unlock them.