When your customers add both pre-order items and in-stock items to their cart, it creates what's called a "mixed cart order" on Shopify. Most 3PLs don't directly support Shopify mixed cart orders that contain pre-orders with the "Scheduled" status - you will likely require a special workflow to ensure it integrates with your operations.

In this article, we'll look at the solutions for Shopify mixed cart pre-orders if you're using a 3PL for fulfillment.

What are Shopify mixed cart orders?

Mixed cart orders occur when your customers purchase:

• Pre-order items (not yet available)
• In-stock items (ready to ship immediately)
• All in the same transaction

This creates fulfillment challenges because you have items with different availability timelines in a single order.

For more details about what happens in these scenarios, see our help article: What happens if a customer purchases an in-stock item and a pre-order item with different fulfillment dates on Shopify?

The shipping cost challenge

Let's look at how Shopify handles fulfillment status - which is crucial for managing shipping costs. If you have the Shopify Split Shipping in Checkout feature enabled, the following applies:

Pre-order (specific date) + in-stock item:

• Results in TWO separate fulfillments (sub-orders) by default
• The pre-order item is assigned with the "Scheduled" status (signals to Shopify you're running proper pre-orders)
• The in-stock item is assigned with the "Unfulfilled" status
• Customer pays shipping twice (once for the Scheduled shipment + once for the Unfulfilled shipment)
• Items are shipped separately by default

If you don't have the Shopify Split Shipping in Checkout feature enabled and you're not using a pre-order app to run pre-orders*, the following applies:

Pre-order (ASAP) + in-stock item:

• Results in ONE combined fulfillment
• Customer pays shipping once
• Items are shipped together when the pre-order stock arrives

*By default, our Early Bird app helps assign your pre-orders with the "Scheduled" status, but you also have the option to assign the "Unfulfilled" and "On Hold" statuses to your pre-orders if you'd like.

For a detailed explanation of these order statuses and their implications, see our help article: What are the differences between Scheduled, Unfulfilled, and On Hold Shopify order statuses?

Solution 1: Assign your Shopify pre-orders with the "Unfulfilled" status and ship everything together

Most 3PLs does not support Shopify mixed cart orders - i.e. orders that have items with the "Scheduled" status and items with the "Unfulfilled" status. Some may not even recognise items with the "Scheduled" status, so the best solution is to switch all your pre-orders' assigned status to be "Unfulfilled" by default.

You may also want to put your in-stock items "On Hold" instead of leaving them as "Unfulfilled", to avoid Shopify and its banking partners raising questions as to why you've taken customers' payments but haven't shipped their items yet.

If you're using Early Bird as your Shopify pre-order app, here's how to set up a campaign to achieve to above:

Setting up unified fulfillment

Step 1: Configure your pre-order campaign

1. Go to campaign settings > Fulfillment section
2. Select "As soon as possible" instead of a specific date
3. This ensures your pre-orders will get assigned the "Unfulfilled" status like in-stock items

Step 2: Create display override for product page

1. On campaign dashboard > Top right > More actions > Customize display
2. Create override
3. Under "Deferred fulfillment date notice," you can add custom text showing the actual expected ship date
4. This replaces the generic "ASAP" with your specific timeline
5. Note this only changes the display on your Product page, not in cart or checkout.

Step 3: Create display override for in cart and at checkout

1. Go to Early Bird's Localization settings > Information
2. Update the ASAP field to your preferred generic custom text (e.g. "2-4 weeks")
3. This text will be displayed as a line item in cart and at checkout (e.g. "Expected ship date: 2-4 weeks")
4. Note this won't change the display on your Product page, but applies globally to all pre-order items in cart and at checkout

Step 4: Set up inventory holds

• You can configure your fulfillment system to hold in-stock items until pre-order stock arrives
• Use Shopify Flow or manual processes to prevent early shipment of in-stock items
• Coordinate with your 3PL about handling these orders

For automatically or manually holding all fulfillments to ship pre-order and in-stock items together, see our help article: How do I hold all fulfillments to ship in-stock and pre-order items together on Shopify?

Managing customer expectations

Clear communication is essential when you're not shipping your customers' in-stock items right away. You can include messaging in:

Shopify Product page description:

• "When ordered with pre-order items, all products will ship together when the pre-order items arrive at the warehouse"
• Display the unified shipping timeline prominently

Shopify Order confirmation email:

• Explain the combined fulfillment process
• Confirm the expected ship date for the entire order
• Thank customers for their patience

Shopify Pre-order policy page:

• Detail your mixed cart shipping approach
• Explain why items ship together (cost savings, convenience)
• Provide timeline expectations

Shopify Purchase agreement option label at checkout:

• Display shipping terms before purchase completion
• Ensure customers understand the combined fulfillment

For a step-by-step guide on how to edit your Order confirmation email, Pre-order policy, and Purchase agreement options label, please visit and search our help centre for the respective articles.

Solution 2: Shopify's Split Shipping (for immediate fulfillment needs)

Some of your customers may prefer to receive their in-stock items immediately and pre-orders separately, and happy to pay for the shipping twice. Shopify introduced the Split Shipping in Checkout feature for scenarios like this.

When to use Shopify's Split Shipping in Checkout

• Many of your customers have requested immediate shipment of available items
• In-stock items are time-sensitive (perishables, seasonal items)
• You have multiple fulfillment locations stocking different products (which would trigger split shipping by default)
• You have multiple shipping zones/rates

For a comprehensive guide on how to implement Shopify Split Shipping, you can view our help article: Shopify Split Shipping: How to Manage Pre-orders and In-Stock Items in One Order or our YouTube video: How to Ship Mixed Cart Pre-orders on Shopify (Split Shipping in Checkout)

Setting up Split Shipping

To enable this Shopify's built-in feature:

1. Go to Settings > Shipping and delivery
2. Enable "Split shipping at checkout"
3. Create separate shipping zones or profiles for different fulfillment timelines

Configure your Early Bird pre-order campaigns:

• Use a "specific date" fulfillment for pre-orders (this assigns them with the "Scheduled" status)
• Keep in-stock items as normal inventory ("Unfulfilled" status)
• This automatically creates separate fulfillments
• Note the separate fulfillments are only sub-orders, not actual split orders

From the 3PLs we've seen our merchants use, pre-orders with the "Scheduled" status will sit in a separate list until it's ready to be fulfilled as an in-stock item ("Unfulfilled" status).

Once the pre-order items have reached the specific date for fulfillment, Shopify will automatically switch their status from "Scheduled" to "Unfulfilled". Your 3PL's system should then be able to process it as a normal order.

Real merchant example

Here's an example of how Shopify mixed cart fulfillment works in practice, from one of our merchants:

Customer places order: Black hoodie (pre-order) + Bush camo shorts (in-stock)

Technical flow with their 3PL:

1. The pre-order is created with the "Unfulfilled" status at the 3PL's location
2. The In-stock shorts are held at the 3PL's location until hoodie arrives
3. When pre-order stock arrives, the stock is deducted from Available to Committed at the 3PL's location
4. Since the 3PL doesn't have the pre-order stock yet, it'll give the merchant a "Request declined" status
5. Once the restock lands at the 3PL location, the merchant submits "Request fulfillment" for the order
6. The 3PL ships the entire order together
7. Customer pays one shipping cost

Important risks and considerations

Shopify account risk: Using Shopify's "Unfulfilled" status for pre-orders that extend beyond a 30-day fulfillment windows could potentially raise questions from Shopify. In extreme cases, this might risk putting your Shopify account on hold.

Banking and compliance: Extended pre-order periods using Shopify's "Unfulfilled" status also may not align with standard e-commerce fulfillment expectations from yourpayment processors.

For more info on how to avoid your Shopify account being put on hold after running pre-orders, see our other blog article: Shopify Pre-Order Account Hold: Why It Happens and How to Fix It

Why does this workaround exist then?

The core issue driving these complications is that many 3PLs don't support fulfillment of Shopify mixed cart orders. In an ideal world, the 3PL should be able to support mixed cart oders that contain:

• Pre-order items ("Scheduled" status)
• In-stock items ("Unfulfilled" status)

3PL systems often can't handle these mixed status orders, forcing merchants to use "Unfulfilled" for everything as a workaround.

Are there any other alternative solutions?

We also looked at Shopify Flow automation as another potential solution:

• Flow would enable sending additional order information to 3PLs
• But requires the 3PL's technical support for custom HTTP requests
• Could eliminate the need for the Shopify's order status workaround in this article
• But it depends on your 3PL's technical capabilities and willingness to integrate

If you're own or work for a 3PL that supports Shopify's mixed cart orders, we'd love to have a chat and recommend you to our merchants in the future.

Risk mitigation strategies

Shortened pre-order windows: Consider reducing your pre-order timeline to minimize risks associated with the "Unfulfilled" status approach.

30-day shipping guideline: When using "Unfulfilled" status for pre-orders, try to ship within 30 days from payment capture. This helps:

• Maintain customer satisfaction
• Reduce potential issues with payment processors
• Align with Shopify's standard e-commerce fulfillment expectations
• Minimize your risk of account complications

Clear customer communication: It's completelyfine to over-communicate shipping timelines and policies to set proper expectations with your customers.

Monitor account health: Document and keep track of everything you've implemented for the "best pre-order practices" so you can show and explain to the Shopify team if questioned.

3PL integration best practices

A typical 3PL's fulfillment for mixed cart orders (all orders assigned with the "Unfulfilled" status) will look something like this:

• You'll see an initial "Request Declined" status as your pre-order stock isn't available at the 3PL's location yet
• Manually select "Request Fulfillment" action in each mixed cart order's details page once the stock arrives at the 3PL's location
• Communication with your 3PL about hold procedures for the in-stock items in the mixed cart orders

Inventory management: 3PLs will correctly deduct stock from "Available" to "Committed" when orders are placed

Final thoughts

Our Early Bird merchants using this "Unfulfilled" status method have never experienced issues with Shopify, hence we've published this blog article!

Not sure if your 3PL can handle the fulfillment workflow for Shopify mixed cart pre-orders properly? Get in touch with us at support@shopside.com.au and we'd be happy to have a chat with your 3PL so you can run pre-orders with peace of mind.