The request
“We use minimum order quantities. Some products have a minimum of twelve, others twenty-four. The cart should enforce it and tell customers what the minimum is.”
Minimums communicated but not enforced.
The approach
We enforced per-product minimums in the cart with quantity fields that won't go below them, a message showing the minimum, and checkout blocked until every line meets it.
What we shipped
Per-product minimum quantities enforced
Minimum shown on product and cart
Checkout blocked until met
Managed from the product admin