1. What is Quantity rules?
Quantity rules let you control the minimum, maximum, and increment quantity that B2B customers can order for a product - for example, requiring a minimum order of 5 units, sold only in increments of 5.
Quantity rules are Shopify's native B2B catalog feature. There's no Theme Editor setting for them - you configure the Min, Max, and Increment values in Shopify Admin, and the theme automatically enforces and displays them everywhere a customer can choose a quantity: the product page, product cards, cart, Quickview, Sticky add-to-cart, Bulk order, and Quick order list.
Note: Quantity rules are only enforced for customers logged in as B2B and assigned to a catalog with quantity rules configured. Regular storefront visitors and non-B2B accounts always use the default Min 1 / Increment 1, with no maximum.
2. Where you'll see it
| Product page | The quantity selector defaults to the Min value, and the +/β buttons step by the Increment. This applies wherever a quantity selector appears: Buy buttons, a standalone Quantity block, and Sticky add-to-cart - across the Product information, Product three columns, Product showcase, and Quickview. |
|---|---|
| Product cards | Cards with a quantity selector follow the same Min/Increment behavior. Cards without one add the Min quantity automatically when "Add to cart" is clicked. Horizontal product cards also show a rules tooltip. |
| Cart drawer & Cart page | Quantity fields enforce the same rules. Invalid entries are auto-corrected a few seconds after typing, instead of showing an inline error immediately. |
| Bulk order | Quantity rules text and the Volume pricing tooltip appear next to each product row, and the quantity selector enforces the assigned rule. |
| Quick order list | Same enforcement as Bulk order - Min, Max, and Increment are shown and applied per product row, with the Volume pricing tooltip available where configured. |
3. Location & Setup
Quantity rules are configured per product inside a B2B catalog, not in the Theme Editor. To set them up:
STEP 1: In your Shopify admin, go to Markets > Catalogs.
STEP 2: Create a new catalog or open an existing one, and assign the relevant products and companies to it.
STEP 3: Under the Products section, find the product, click the Plus (+) sign under the Rules column, and set your Minimum, Maximum, and Increment values.
STEP 4: Click "Save".
π For the full walkthrough, see Shopify's official guide:
π Set up quantity rules in Shopify B2B Catalogs
Note: Shopify requires Minimum β₯ Increment. If a product is assigned to multiple catalogs, the rules (and price) from whichever catalog has the lower price are the ones applied.
4. Highlight Features
- Automatically enforces Min, Max, and Increment quantities across every part of the storefront - no extra theme setup required.
- Clear, real-time validation messages guide customers to a valid quantity as they type.
- Supports rules set at the parent product level (applies to all variants) or per variant.
- Shows a "price per item" note next to the quantity box, reflecting the applicable Volume pricing tier.
- Works consistently across the product page, product cards, cart, Bulk order, and Quick order list.
5. Common Use Cases
π€ How does the quantity selector behave with quantity rules applied?
When a B2B customer views a product with quantity rules configured:
- The quantity selector defaults to the Min value.
- Clicking "+" increases the quantity by the Increment each time (e.g., Min 3 / Increment 3 β 3, 6, 9...).
- Clicking "β" decreases by the Increment, and disables once the quantity reaches Min.
- If a Max is set, quantity can't be increased past it. If no Max is set, customers can add up to the available inventory.
If neither the product nor its variant has a rule configured, the selector falls back to the default: Min 1, Increment 1, no Max.
π€ What happens when a customer types an invalid quantity?
The theme validates quantity input and shows one of these messages:
| Situation | What the customer sees |
| Entered below Min | "Value must be greater than or equal to <min>." Clicking away from the field auto-fills the nearest valid value. |
| Entered above Max | "Value must be less than or equal to <max>." Clicking away auto-fills the nearest valid value. |
| Not a multiple of the Increment | "Please enter a valid value. The two nearest valid values are <X> and <Y>." |
Note: In the Cart drawer and Cart page, invalid quantities aren't corrected instantly - the field auto-verifies and corrects itself a few seconds after the customer stops typing.
π€ How do quantity rules work with product variants?
- Parent sets a shared rule: All variants use the same Min/Max/Increment.
- Parent has no rule, variants set their own: Each variant uses its own rule. Switching variants updates the quantity selector and tooltip to match - it doesn't keep the previous variant's values.
- Neither parent nor variant has a rule: The selector uses the default (Min 1, Increment 1, no Max).
- Switching variants with a custom quantity already entered: The quantity automatically adjusts to the nearest valid value under the new variant's rule.
π€ How do quantity rules interact with Volume pricing?
When a product has both quantity rules and Volume pricing configured:
- A "price per item" note appears to the right of the quantity box, showing the unit price for the currently selected quantity tier.
- Changing the quantity updates this price automatically to match the applicable Volume pricing break (including its compare-at price, if one is set in the catalog).
- If the product only has quantity rules and no Volume pricing configured (price breaks left blank), no pricing tooltip is shown - only the quantity rule itself applies.
For the full breakdown of the Volume pricing table and its settings, see our Volume pricing guide.
π€ Do quantity rules apply the same way in Bulk order and Quick order list?
Yes. Both sections show the Min/Max/Increment text and a Volume pricing tooltip (where configured) next to each product's quantity field, and enforce the same rule when the quantity is changed. In the Bulk order search popup specifically, the per-unit price updates as soon as a quantity that matches a Volume pricing tier is entered.
See our Bulk order guide and Quick order list guide for the full setup of those sections.
π€ Are there exceptions - unavailable variants, sold-out items, or gift cards?
- Unavailable variants (a variant combination that can't be selected or purchased at all): the quantity selector ignores quantity rules and always steps by 1, and the Volume pricing block is hidden.
- Sold-out variants (a valid variant that's simply out of stock): quantity rules still apply normally - the Increment is not reset to 1.
- Gift cards: quantity rules apply the same way as on a simple product.
π€ What happens if I also use "Login to see price"?
If a product's price is hidden by Login to see price, all price-related information tied to quantity rules is hidden too - this includes the "price per item" note, the Volume pricing tooltip on product cards, and the Volume pricing table itself. If price is hidden, the Quick order list section is hidden entirely, since it's built around showing pricing at a glance.
6. Change logs
Version 2.0.0 - August 2026
- New β Quantity rules: Introduced automatic enforcement and display of Shopify B2B catalog quantity rules (Min, Max, Increment) across the product page, product cards, cart, Bulk order, and the new Quick order list.
7. Support Information
Need help? Contact our support team at Omni Themes Support
