How to Set Up a Build-a-Box Mix and Match Bundle on Shopify

To set up a build-a-box bundle on Shopify, choose one collection of eligible products, fix the box sizes a shopper can fill, set a price or discount for each size, and make sure that discount is applied automatically at checkout. The shopper picks the contents; you control which products qualify and what each count costs. This guide walks through the mechanics, the pricing, stock, where to show the builder and which catalogues the format suits.

How does a mix and match bundle work?

The shopper chooses a set number of items from a pool you define, and the offer applies once the count is reached. 'Any three candles' and 'pick six bars' are the same mechanic at different sizes.

Three parts make up the offer:

• The pool: the products or collection a shopper may choose from.
• The count: how many items make a box, often with more than one size.
• The reward: the price or discount that applies when the count is met.

Which products should be eligible?

Products that are close in price, margin and size. The box has one price rule, so every item in the pool has to make sense under it.

• Keep prices in a narrow band. If the pool mixes a $4 item with a $12 item, shoppers will fill the box with the expensive one and your discount lands where it costs most.
• Check the worst-case box. Work out the margin on a box filled entirely with your highest-cost eligible item. If that box loses money, tighten the pool or the price.
• Use a dedicated collection. A collection created for the box lets you add and remove products without touching the offer.
• Leave out anything awkward to pack with the rest: fragile, oversized or temperature-sensitive items.

Say a snack brand sells bars at $3 each and offers any six for $15. As example figures, the bars cost between $0.90 and $1.60 to make. A box of the cheapest bars costs $5.40 in product; a box of the dearest costs $9.60. The offer has to work at $9.60, because some customers will build exactly that box.

How should you price by count?

Either as a set price per box or as a discount that unlocks at each count. Which one fits depends on how uniform the pool is.

• Set price per box suits pools where everything costs the same: any six for $15. It is the easiest to read.
• Percentage off at a count suits pools with some price variation: pick four, save 15 percent. The saving scales with what the shopper chose.

Two or three box sizes are enough. Make the larger box the better deal per item, and check profit per order at each size the same way you would for any tiered offer; our guide to setting quantity break tiers shows the sum.

Decide early whether a shopper may pick the same item more than once. Allowing repeats suits consumables, where people have a favourite. Requiring different items suits sampler boxes meant for discovery.

How do you keep every choice in stock?

Treat each choice as what it is: its own product with its own inventory. A box is only as available as the items people want to put in it.

• An item that sells out should drop out of the builder or show as unavailable, not sit there waiting to cause an error at checkout.
• Watch the favourites. Mix and match concentrates demand on a few popular choices, and those run out first.
• Keep the pool wide enough that one sold-out item does not make the box impossible to fill.

How the sale is recorded matters to your warehouse. Our explainer on how bundle inventory tracking works on Shopify covers the two models and what each means for picking.

Should the builder sit on a product page or its own page?

A dedicated page when the box is a product in its own right; the product page when the offer is a nudge to add more from the same range.

• Dedicated page. Give it a place in the navigation and use it as the landing page for campaigns. The shopper arrives intending to build a box, so the page can be all builder: the pool, a running count and the price so far.
• Product page. Someone viewing one candle sees 'add any two more and save'. The box is a suggestion beside the main purchase, so it must stay compact.

In both places, show progress. The shopper should always know how many items are chosen, how many remain and what the box will cost. For layout detail, see how to display bundle offers on a product page.

Which categories suit build-a-box?

Ranges with many similar items, low unit prices and tastes that vary.

• Snacks and drinks: flavours are personal, and a box lets people take a risk on one new flavour beside five they know.
• Socks and basics: same size, same price, many colours or patterns.
• Skincare minis and samples: small formats built for trying several before committing to a full size.

Setting it up

1. Create a collection that holds only the eligible products.
2. Choose the box sizes and the price or discount for each.
3. Run the worst-case margin check on each size.
4. Create the offer and place it on the page you chose.
5. Place a test order and confirm the total at checkout matches the page.
6. Check how the order appears to whoever picks and packs it.

Marka Bundles & Upsells includes mix and match across products or collections as an offer type. Offers are created in the Shopify admin, shown through an app block added from the theme editor, and discounted at checkout by Shopify Functions without a code.

A short checklist

1. One pool, with prices and margins in a narrow band.
2. Two or three box sizes, the larger one better value per item.
3. A margin check on the most expensive possible box.
4. A rule on whether repeats are allowed.
5. Sold-out choices hidden or clearly marked.
6. A running count and price visible while the shopper builds.

Mix and match is one of several bundle formats, and the guide to Shopify bundle types explains when a fixed set or a quantity break is the better choice. If a box fits your range, Marka Bundles & Upsells is where to build it.