Bundle upsell: offer the multipack in the cart

When a shopper puts a single item in their cart and you also sell that item as

a multipack, Multipacks can offer them the upgrade right there in the cart —

usually at a better per-unit price. One click swaps the singles for the pack.

Plan: Bundle upsell is a Pro feature. On the free plan the Upsell page

shows an upgrade prompt instead of the settings.

Before you start

You need all four:

• The Pro plan. Multipacks app → Plan.

• An Online Store 2.0 theme. Most themes released since mid-2021 qualify

  (Dawn, Refresh, Horizon, Sense, Craft and similar). Vintage themes cannot run

  the cart features.

• The Cart bundle manager app embed, switched on in your theme.

• At least one bundle configured in Multipacks, so the app knows which

  singles make up which pack.

Turn it on

1. Grant the theme permission (if you are asked)

Open the Multipacks app → Upsell. If you see a yellow banner reading

"Additional permission needed", click Re-authorize and approve.

Multipacks needs to read your theme to know whether it can run in your cart.

Until that is granted, the Bundle upsell switch stays greyed out. Shops

installed recently already have this and will not see the banner.

2. Switch on the app embed in your theme

1. Shopify admin → Online Store → Themes.
2. On your live theme, click Customize.

3. In the left sidebar, click App embeds (the puzzle-piece icon at the

   bottom).

4. Switch Cart bundle manager on.
5. Click Save.

The Multipacks app cannot do this step for you — it never writes to your theme.

If you would rather be taken straight there, the app shows a link that opens the

right panel with the embed pre-selected.

3. Switch on Bundle upsell

Multipacks app → Upsell → set Bundle upsell to Enable.

This is the store-wide switch. Every bundle follows it unless you change an

individual one in the next step.

4. Choose where the offer appears, per bundle

Open any bundle in Multipacks → Upsell CTA placement:

5. Style the offer

Back in the theme editor, expand Cart bundle manager to set:

• Heading — the text above the offer. Default: Save with the multipack.
• Button label — default: Upgrade to bundle.

• Show savings — display how much the shopper saves by upgrading. On by

  default.

• Upsell button style — Filled button or Text link.

• Accent color — optional. Overrides the filled button colour. Leave it

  unset and the offer picks up your theme's own button colour.

• Custom CSS — optional escape hatch if you need a closer match to your

  theme.

Click Save.

Check it works

1. Open your storefront (not the theme preview).
2. Add a single item that belongs to one of your bundles to the cart.
3. Open the cart. The upgrade offer should appear in the placement you chose.

4. Click the upgrade button. The singles are replaced by the multipack, and the

   cart total updates.

Your upsell numbers

Multipacks app → Upsell shows the last 30 complete days, per bundle:

• Shown — how many times the offer appeared.
• Swapped — how many times a shopper took it.
• Swap rate — swapped ÷ shown.
• Cart value — value of the carts that took the offer.

The window ends yesterday. Today is deliberately excluded: a partial day

would read as a sudden drop to near zero. A bundle you have since deleted still

appears, labelled Deleted bundle, so past numbers stay honest.

Troubleshooting

The Bundle upsell switch is greyed out.

Either the theme permission is missing (look for the Additional permission

needed banner and click Re-authorize) or your theme is not Online Store

2.0. The app tells you which in a banner above the switch.

Nothing appears in the cart.

Work down this list:

1. Is the Cart bundle manager app embed on and saved in your live

   theme? Saving in a preview or an unpublished theme has no effect.

2. Is Bundle upsell enabled in the Multipacks app?
3. Is the item in the cart actually a component of a configured bundle?
4. Is that bundle's Upsell CTA placement set to Off?
5. Is the bundle itself active in Multipacks?

The offer appears but the upgrade button does nothing.

Some themes re-draw the cart after every change, which can remove the offer

mid-click. Tell support your theme name and version — this is fixable on our

side.

Savings show as zero or look wrong.

Savings compare the bundle's price against the same number of units bought

singly. If the bundle is not actually cheaper per unit, there is nothing to

show. Check the bundle's price in Shopify.

Still stuck? Contact Multipacks support with your shop name, your theme

name, and the product involved.