Per-Product Quantity Rules WordPress Function

What it does?

• Admin UI for quantity rules
  Adds a “Quantity settings” toggle on the product editor (simple & variable). When enabled, shows fields for Min Qty, Max Qty (supports unlimited), and Step. Includes a small script to reveal/hide the fields instantly.

• Saves rules per product
  Stores the chosen min/max/step so editors can manage MOQs, case packs, or wholesale increments per SKU.

• Applies rules on single product pages

  • Sets the quantity input’s min, max, and step.

  • Uses the min as the default input value (outside the cart), so customers start at the correct quantity.

  • Caps max by real stock when stock is managed and backorders are disallowed.

• Works with variations
  Inherits the parent product’s rules and exposes min_qty / max_qty to the variation data. For stock-managed variations without backorders, max is further limited by the variation’s stock.

• Shop/Archive add-to-cart
  For AJAX add-to-cart buttons in product loops, forces the min quantity so quick adds honor your rules.

Why it’s useful?

• Stop odd or unprofitable orders
  Enforce minimum order quantities, carton multiples, and clean increments to protect margin and packing efficiency.

• Consistent UX, fewer errors
  Customers see valid quantities everywhere (product, variations, and loop), reducing cart validation errors and support tickets.

• Operational fit
  Aligns storefront behavior with warehouse realities (e.g., sell in 6-packs, cap buys to available stock).

• Granular control
  Tune rules per product instead of a one-size-fits-all approach.