What happens if a customer types an invalid quantity?

The input snaps to the nearest valid multiple and a short toast explains why — for example 'Adjusted to 6 (must be in multiples of 6)'. The customer isn't left guessing, and the rule is also enforced server-side at native Shopify checkout, so an invalid quantity can't get through by editing the cart URL or using a wallet.

Can I set a step on one variant but not another?

Yes. Step quantity is set per product or per variant, and variant-level rules take precedence. Switching variants on the product page re-applies the correct rule for the newly selected variant.

Does it work on collection pages and quick-add buttons?

Yes. The rule applies anywhere a customer can add to cart — the product page, collection grid cards, theme quick-add forms, the mini-cart, and the cart page — not just the PDP.

Which themes are supported?

Step quantity works on Dawn, Refresh, Sense, Craft, Crave, Trade, Origin, Studio, Ride, Colorblock, Taste, Publisher, Spotlight, and Shopify's newer Savor and Horizon themes. Product-page detection is structural rather than theme-specific, so it works out of the box on modern themes, and you can supply a custom CSS selector in Settings if your theme is unusual.

Can I import step quantities in bulk?

Yes. The product-limit CSV import and export include a stepQuantity column, so you can set case packs across a large catalog in one upload. See CSV Bulk Import & Export.

Which plan includes step quantity?

Pro. Step quantity and increment rules are part of the Pro plan's product-limit set and are also included on Advanced.

Step Quantity & Case Packs

3 min read

Sell in Fixed Multiples

A step quantity rule means a product can only be bought in multiples of N — case packs of 6, six-packs, dozens, pallets. It's the rule for wholesale minimums, packaging that ships in fixed counts, and anything where a partial case creates a fulfillment problem.

Step quantity is enforced in three places: the storefront input snaps to a valid number, the badge tells the customer the rule before they add to cart, and native Shopify checkout rejects an invalid quantity server-side.

How to Set Up

Go to Product Limits
Find the product or variant
Enter the multiple in Step quantity — for example 6
Optionally set a minimum order quantity alongside it
Click Save

Example: Case Pack of 6

Rule:  Step quantity 6 on "House Blend 250g"

Customer types 5  -- snaps up to 6, toast: "Adjusted to 6 (must be in multiples of 6)"
Customer types 9  -- snaps to 12
Customer clicks - -- steps down to 6
Checkout with 7   -- blocked server-side

Combining Step and Minimum

The two rules stack. The minimum sets the floor; the step sets the interval above it.

Minimum: 12
Step:    6

Valid:   12, 18, 24, 30 ...
Invalid: 6 (below the minimum), 15 (not a multiple of 6)

What Customers See

On the product page:

📦 Order in multiples of 6

When they type an invalid quantity:

"Adjusted to 6 (must be in multiples of 6)"

At checkout, if an invalid quantity gets that far:

"This product must be ordered in multiples of 6."

All three messages are customizable under Settings → Storefront Messages, and shoppers see them in their own language — see Languages & Translations.

Where the Rule Applies

Surface	Enforced
Product page quantity input	Yes — snaps to a valid multiple
Collection grid and quick-add	Yes
Mini-cart and cart page	Yes
Native Shopify checkout	Yes — server-side, cannot be bypassed

Bulk Setup

For large catalogs, use the CSV import — the stepQuantity column sets the multiple per product or variant in one upload. See CSV Bulk Import & Export.

Tips

Set the step on the variant when case sizes differ by size or format
Pair a step with a per-customer limit when you also need to cap how much one buyer takes
If your theme uses unusual markup, set a custom product-page selector in Settings rather than editing theme code

Collection Limits Minimum Order Quantity (MOQ)