How to set up Simple Bundles with your 3PL or WMS

A smooth order management process is key, especially when you're working with a 3PL or WMS, such as ShipHero, Cin7, NetSuite, etc. These systems rely on accurate order and inventory data to correctly pick, pack, and ship products, as well as to update fulfillment statuses in Shopify.

Here's what we're covering:

How bundles are added to orders in Simple Bundles 2.0
Handling fulfillment for orders from sales channels or third-party apps
Sending fulfillment requests to your 3PL
Inventory management with 3PLs
If you're using Simple Bundles v1.0

How bundles are added to orders in Simple Bundles 2.0

By default, Simple Bundles 2.0 uses Shopify's Cart Transform API to add bundle items directly to the order at checkout, before the order is created. This is a significant improvement over the order-editing approach used in 1.0, since the bundle's components are added to the order as real, native line items from the start, which is far more compatible with 3PL/WMS systems that rely on standard order data rather than post-creation edits.

With Cart Transform, your 3PL/WMS receives the order already containing the correct component SKUs, with no separate order edit event to detect or sync. This resolves the most common integration pain point from 1.0, where 3PL systems that didn't listen for Shopify's order edit webhook would miss bundle components entirely.

To enhance integration further, you can enable Bundle Details in Shopify Order Metafields.

Handling fulfillment for orders from sales channels or third-party apps

Some orders, especially those created by third-party apps or sales channels like Facebook, Instagram, TikTok, Amazon, or ReCharge for subscriptions, can't be edited due to Shopify's limitations, since Cart Transform can't run on orders that are created directly via API by another app or that involve subscriptions/selling plans. In these cases, Simple Bundles automatically falls back to the Order Editing method instead.

With Order Editing, the parent bundle line stays on the order at full price, and its components are added alongside it at a 100% discount. If the original order itself can't be edited (common for marketplace-synced orders), Simple Bundles creates a separate associated order to hold the components, identifiable by an "A" suffix on the order number, containing reference custom line items with the bundle name, the customer's shipping details, and a note linking back to the original order.

For more detail on this behavior, see: Handling orders that cannot be edited by Shopify.

Sending fulfillment requests to your 3PL

If your Shopify store is connected to a 3PL or WMS, you might want to automatically trigger fulfillment for orders that include bundle items.

If you'd prefer not to send the parent bundle line to your 3PL (relevant for Order Editing/associated order scenarios), you can enable automatic fulfillment of bundle SKUs instead. This automatically marks the parent bundle line as fulfilled, so your 3PL/WMS only needs to process the actual component SKUs, rather than treating the parent line as something that also needs to be picked and packed.

To enable this in 2.0, go to: App settings > Manage Advanced Settings > Order Editing and Cart Transform fallbacks > Manage, and locate the section titled "Order fulfillment when Cart Transform function does not run."

Enabling automatic fulfillment of bundle SKUs

Note: There is also a separate "automatic fulfillment of bundle components" setting. This is different from automatic fulfillment of bundle SKUs; if enabled, it will mark your real, physical components as fulfilled automatically too, not just the reference parent line. Most merchants using a 3PL/WMS will only want automatic fulfillment of bundle SKUs enabled, since your components genuinely need to go through your real fulfillment process.

Inventory management with 3PLs

Simple Bundles doesn't sync inventory directly with 3PL apps, but it pulls data from Shopify. So, if your 3PL updates item stock in Shopify, that update will be reflected in the bundle inventory as well, as long as Shopify is the source of truth for that inventory update.

Some 3PL/fulfillment apps manage their own Shopify location with the inventoryManagement flag set so that only that app can write inventory there. If this applies to your 3PL, Simple Bundles won't be able to read or sync inventory at that location. Ask your 3PL whether they're able to set inventoryManagement to false at their managed location; if they can't, you may need to disable Track quantity or enable Sell when out of stock on the parent bundle as a workaround, with oversell protection still applying at checkout via Cart Transform.

Simple Bundles 2.0 also uses location-based inventory by default: a bundle's components need to be stocked at the same location as the bundle itself for its inventory to calculate correctly. Be sure your bundle product is stocked at the same location(s) as its individual components. You can check this in Shopify by going to Edit locations for both the parent product and its components.

If you notice your bundle inventory resetting to zero or showing incorrectly, check out this guide: Troubleshooting bundles showing as out of stock in Simple Bundles.

Using Simple Bundles v1.0?

If you are on Simple Bundles v1.0, which relies on order editing for all orders (not just ones Cart Transform can't handle), the same associated order and Single-SKU concepts apply, but v1.0 does not have Cart Transform available at all. If these items aren't syncing after the original order has been edited, it might be because your 3PL or WMS is not listening to Shopify's order edit webhook.

In those cases, if you'd prefer to avoid dealing with order edits or want to disable the creation of an associated order to include bundle items, go to your Preferences page, navigate to the Orders section, and uncheck "Enable creation of a new order if the Shopify order cannot be edited."

You can also consider using the Single-SKU feature as a workaround for Simple Bundles v1.0, where the bundle product and its components are identified by only one SKU during fulfillment. This option is best if your bundles are already pre-packaged and ready to ship, as your fulfillment team won't need to search for individual components. You can still choose to show the itemized bundle contents on packing slips, even if these items are not added to Shopify orders.

If your orders are placed through Shopify's online store checkout or Shopify POS, we'd strongly recommend migrating to Simple Bundles 2.0, since Cart Transform resolves most of the integration friction described in this section entirely. See: An Introductory Guide to Simple Bundles 2.0.