Multi-Collection Sale for Shopify — Different Discounts Across Collections

How it works

Multi-Collection Sale lets you run different discount percentages across multiple collections simultaneously — all managed as a single promotion. Each collection gets its own sale percentage. Then, optionally, you can layer two more tiers on top: a cross-collection volume unlock (buy enough items from any of the sale collections and everything drops further), and a flat-price conversion (buy even more and every item converts to a fixed price).

The app handles all the logic automatically. If a product appears in more than one of your sale collections, it gets the highest applicable discount. If a flat-price tier applies, no item will ever be priced higher than its already-discounted price — cheaper items keep their better deal.

Shopify has no native way to do any of this. Its discount system applies one discount per product — you can't assign different percentages to different collections in the same promotion, let alone layer volume tiers on top. Custom Promos runs the entire calculation inside Shopify's checkout infrastructure using Shopify Functions, so customers see accurate pricing in real time.

🏪 Example: End-of-Season Layered Sale

You're running a layered end-of-season event: Shoes 50% off, "Last Ones" clearance 75% off. Buy 5+ items from either collection and everything goes to 80% off. Buy 8+ items and every item is just $20.

Here's what a customer sees when they add 5 items — 3 shoes and 2 clearance items:

🛒 Shopping Cart — Volume Unlock Active: 80% OFF EVERYTHING

Leather Ankle Boot (Shoes · was 50% off)$148.00$29.60

Block Heel Sandal (Shoes · was 50% off)$89.00$17.80

Pointed Flat (Shoes · was 50% off)$72.00$14.40

Silk Blouse (Last Ones · was 75% off)$95.00$19.00

Linen Trousers (Last Ones · was 75% off)$110.00$22.00

Total$514.00 $102.80

✓ 5 items triggered the 80% volume unlock across both collections. The customer saved $411.20.

The three layers — use any combination

Layer 1 — Per-collection discounts (required)

Add two or more collections, each with its own percentage. Shoes at 50%, clearance at 75%, new arrivals at 20% — all active at once under one promotion.

Layer 2 — Cross-collection volume unlock (optional)

Set a threshold: when the customer buys N or more items across any of your sale collections combined, everything in the promotion bumps to a higher percentage. The volume threshold counts across all collections — one cart, one deal.

Layer 3 — Flat-price conversion (optional)

At a higher item count, every qualifying item converts to a fixed dollar price. Great for "everything $20" events. Items already cheaper than the flat price keep their better deal — the flat price never raises what a customer pays.

Real-world use cases

🛍️ End-of-Season Event

Regular sale items at 40% off, end-of-life clearance at 70% off. Buy 5+ items from either and everything goes to 80% off. Clears two categories of inventory in one promotion.

👗 Trunk Show Layered Sale

Featured designer 30% off, last season's styles 60% off. Mix and match — the volume unlock rewards customers who build a full outfit regardless of which collection it comes from.

📦 Everything Must Go

Multiple clearance collections each at their own percentage. Hit 8 items and everything converts to a flat $15. The kind of event that clears a stockroom in a weekend.

🎉 VIP Preview Sale

New arrivals at 20% off, last season at 50% off. Run it for loyalty customers before a public sale — the cross-collection volume bonus encourages outfit-building across both ranges.

Setting it up takes 2 minutes

Select "Multi-Collection Sale"

Choose this promotion type from the new promotion screen.

Add your collections

Use the visual collection picker to add two or more collections. Set a discount percentage for each one.

Add a volume unlock (optional)

Set how many items — across all your sale collections combined — trigger the bonus percentage.

Add a flat-price tier (optional)

Set a higher item count and a flat dollar price. Items cheaper than the flat price keep their better deal automatically.

Activate

Hit save. The promotion goes live instantly across all your selected collections.

How overlapping products are handled

If a product lives in more than one of your sale collections, it automatically receives the highest applicable percentage. You don't need to worry about which collection "wins" — the app always gives the customer the better deal.

When the flat-price conversion tier is active, the same logic applies in reverse: an item that's already cheaper than the flat price keeps its lower price. The flat price is a ceiling, not a floor.

Why Shopify can't do this natively

Shopify's discount system applies one discount per product. There's no way to assign different percentages to different collections within the same event, and no way to layer a cross-collection volume threshold on top. Store owners trying to replicate this typically have to create multiple separate discount codes, manually tell customers which to use, and hope nobody stacks them incorrectly.

Custom Promos handles the entire promotion as a single unit. One setup, one activation, and the logic runs automatically at checkout for every customer — no codes, no manual management, no mistakes.

Frequently asked questions

Can I run different discount percentages on different collections at the same time on Shopify?

Not with Shopify's native discounts — it applies one discount per product and can't assign different percentages to different collections in a single event. Custom Promos lets you run, for example, shoes at 50% off and clearance at 75% off simultaneously, all managed as one promotion.

How do I run a storewide sale with different prices per category?

Add each category as a collection in a Multi-Collection Sale and give each one its own percentage. You can then layer an optional cross-collection volume unlock and a flat-price tier on top, so the whole layered event runs as a single promotion.

If a product is in two sale collections, which discount applies?

The product automatically gets the highest applicable percentage. You don't have to decide which collection wins — the customer always receives the better deal.

Does the volume unlock count items across all the collections?

Yes. The volume threshold counts every qualifying item across all the collections in the promotion combined, so a customer mixing items from different collections still works toward the same bonus.

Do customers need to enter a discount code?

No. Custom Promos applies the discount automatically at checkout based on what's in the cart. There's no code for customers to remember, type, or get wrong — they simply see the savings as they shop.

Does this work with Shopify's discount codes?

Your discount codes work normally when no Custom Promos promotion is active. When a Custom Promos promotion is running, discount codes can't be stacked on top of it — this is intentional, to stop customers from combining a promotion with a separate coupon and discounting more than you planned.

Does it work on any Shopify plan?

Custom Promos runs on Shopify Functions, which are available on all standard Shopify plans. You don't need Shopify Plus.

How long does it take to set up?

Most promotions take under two minutes. You pick the promotion type, choose your collection with a visual picker, set your numbers, and activate. No code, no collection IDs, no developer.

Ready to run your layered sale?

Multi-Collection Sale. Per-collection percentages, cross-collection volume unlock, flat-price conversion. Set up in under 2 minutes.

Get Started — $24/mo →

Run a layered sale across multiple collections — each at its own percentage