Gatemi Min-Max Quantities

Set a minimum and/or maximum purchase quantity on any product,
straight from the product’s Inventory tab. One rule engine answers every
surface, so a shopper is never offered a quantity the cart then refuses:

• The quantity selector only offers legal amounts (and starts at the
  minimum), on classic pages and the Cart & Checkout blocks alike.
• Adding to the cart is refused only when it would exceed the maximum —
  counting what the cart already holds, pooled across variations, so a
  limit can’t be beaten by splitting an order over lines.
• The cart check blocks checkout while a quantity is outside its rule —
  and the message names the product, the limit, what’s in the cart and
  exactly how many to add or remove.

Looking for more?

The full edition, Gatemi Min/Max Quantities for
WooCommerce,
adds “sold in multiples of”, per-variation rules, category rules
(inherited by sub-categories), whole-order rules, contradiction
reconciliation, and a one-click importer from WooCommerce Min/Max
Quantities.