Stackable and Shopify discounts
How Shopify discounts work natively, what the platform allows and limits, and exactly where Stackable extends it. Stackable publishes real Shopify discounts; it never bypasses the platform.
The short version: Shopify has a real discount system with types, combination rules, and limits. Stackable builds on top of that system, not around it. Every Stackable campaign becomes a genuine Shopify discount, so everything Shopify guarantees about discounts still holds. This page explains the native system first, then what Stackable adds.
What Shopify offers natively
Out of the box, Shopify gives you four discount types, each available as an automatic discount or a discount code:
- Amount off products: a percentage or fixed amount off specific products, collections, or the whole catalogue.
- Amount off order: a percentage or fixed amount off the order subtotal.
- Buy X get Y: buy a quantity of some items, get other items free or discounted.
- Free shipping: remove shipping charges, optionally over a minimum purchase.
These cover a lot of everyday cases. What they do not cover: quantity tier ladders ("buy 3 for 10 percent, buy 6 for 20 percent"), "2nd item half price", spend goals with several levels, a gift that adds itself to the cart, or any storefront messaging about the deal.
Discount classes: product, order, shipping
Every Shopify discount belongs to one or more classes: product (changes item prices), order (reduces the order subtotal), or shipping (reduces delivery charges). The class controls how discounts can be combined. This is a platform concept, not a Stackable invention; you will see the same three lanes in Shopify’s own admin.
The combinations model
Each Shopify discount declares which classes it agrees to combine with: product discounts, order discounts, and shipping discounts, three independent switches. Two discounts apply to the same order only when each one allows the other’s class, a mutual opt-in. By default, only one product discount applies to any given cart line.
This both-sides rule is exactly the rule behind Stackable’s three "Combine with..." switches. Stackable does not replace Shopify’s combination model; it gives you a clear interface to it and analyses your campaigns against it before you publish.
Platform limits worth knowing
- A store can have a maximum of 25 active automatic discounts, shared store-wide across Shopify’s own automatic discounts and every discount app installed. All of them run independently, with no knowledge of each other. Discount-code discounts do not count toward this limit.
- Shopify’s native Buy X Get Y applies the reward to the lowest-priced qualifying items, the margin-safe choice. Stackable’s default allocation matches this behaviour.
- Discounts never take an item below free. Combining discounts on the same item floors it at zero.
The 25-slot ceiling is why Stackable plans cap how many campaigns can be live at once: the cap keeps you comfortably inside the platform limit even with other discount apps installed. Pausing a campaign frees its slot.
How Stackable publishes discounts
When you publish a campaign, Stackable creates a real Shopify discount on your store through Shopify’s discount platform. You choose how it applies: an automatic discount that fires at checkout for everyone, or a discount-code campaign the shopper enters (which can carry thousands of unique codes). Either way the deal logic runs inside Shopify’s checkout, on Shopify’s infrastructure, at the moment prices are calculated. Only automatic discounts count against the store-wide 25-discount ceiling; code campaigns do not. Stackable never edits your theme’s prices, never applies discounts with scripts on the storefront, and never intercepts checkout.
- Your campaigns appear in the Shopify admin’s discount list, like any other discount.
- Shopify enforces the combination rules and the never-below-free floor.
- Every payment method and checkout flow Shopify supports sees the same prices.
What Stackable adds beyond native
| Capability | Native Shopify | With Stackable |
|---|---|---|
| Quantity tier ladders | Not available | Volume campaigns with multiple tiers and counting modes |
| What "buy 3" counts | Fixed behaviour | Four counting modes: per variant, per product, across matching products, whole cart |
| "2nd item half price" | Not available | Volume with skip-first-units |
| Product bundles | Not available | Fixed bundles and mix-and-match "any few for one price", priced as a real Shopify discount |
| Combination visibility | Switches only | The same switches plus a plain-English order-of-operations explanation and conflict detection across your campaigns |
| Free gift | Manual: shopper must add the gift | The gift adds and removes itself with the cart total |
| Storefront messaging | None | Tier table, badge, countdown, cart progress bar, sale-price display, and bundle builder |
| Testing a deal | Place a test order | A simulator: preview any cart, and the preview matches checkout |
| Scheduling | Start and end dates | Start and end in your store timezone, with statuses that update themselves |
| Starting points | Blank form | A template library of common promotions |
| Measuring results | Order-by-order | Campaign analytics with order attribution via order tags |
The honest framing
Stackable extends Shopify, it does not compete with it. If a native discount already does what you need, it will keep working alongside your Stackable campaigns, subject to the same combination rules as everything else.