Troubleshooting bundles showing as out of stock in Simple Bundles

If your bundle is suddenly showing as out of stock, don’t worry! This is usually caused by a component product’s inventory or a Shopify location setting, and it’s easy to fix. This guide includes:

How bundle inventory works in Simple Bundles 2.0

Common reasons a bundle shows as out of stock and how to fix it

Bundle options showing as 'Unavailable'? Here's what that means and how to fix it

When to use “Continue selling when out of stock”

How to run a manual inventory sync

How bundle inventory works in Simple Bundles 2.0

Simple Bundles 2.0 uses a location-based inventory method. This means that for a bundle to be available for purchase, all of its component products must be in stock within the same single fulfillment location. If even one component reaches 0 inventory at the location used to fulfill the bundle, the entire bundle will show as out of stock, even if stock exists at other locations.

This is by design to prevent overselling and ensure every bundle order can be fulfilled completely from a single location.

For Infinite Options bundles, the app displays the highest possible inventory across all locations on the storefront. However, when a customer adds to the cart or proceeds to checkout, the Cart Transform API performs a real-time check to verify that every selected component is available at a fulfillable location at that moment. If a component is out of stock at a fulfillment location, the oversell protection will block the purchase.

For more information, refer to: Managing bundle inventory and fulfillment for stores with multiple locations

Common reasons a bundle shows as out of stock and how to fix it

1. A component product has 0 Inventory at the fulfillment location

Since Simple Bundles 2.0 uses location-based inventory, the bundle will show as out of stock if any single component has 0 available stock at the location used to fulfill the bundle, even if that component has stock at other locations.

How to check:

1. In Shopify Admin, go to Products → Inventory
2. Search for each component product in the bundle
3. Review inventory per location, not just the total
4. Identify any component showing 0 at the fulfillment location

Solution: Restock the out-of-stock component at the correct fulfillment location. The bundle inventory will update automatically once stock is available.

To troubleshoot and manage inventory across multiple Shopify locations when using Simple Bundles, refer to this guide: Troubleshooting fulfillment issues for multi-location stores using Simple Bundles

2. Parent bundle and components are stocked at different locations

If your bundle parent product is assigned to one location (e.g. Main Warehouse) but one or more components are only stocked at a different location (e.g. Pop-up Shop), Simple Bundles cannot calculate a valid bundle inventory, and the bundle will show as out of stock.

Solution: Ensure the parent bundle product is available at the same location(s) as all of its components. After updating, go to Simple Bundles → Settings and click Resync all bundle quantities.

3. Bundle product not assigned to a shipping profile

If any product included in a bundle, or the bundle parent product itself, is not assigned to a shipping profile, or is assigned to a different shipping profile, Shopify may treat the entire bundle as unavailable.

This issue most commonly affects newly created products, as their underlying SKUs are not always automatically added to an active shipping profile.

When this happens, you may notice:

• The bundle shows as Sold Out on the product page, or
• Customers see an error when trying to add the bundle to the cart, such as a message advising them to check their shipping configuration.

Check a product’s shipping profile assignment

1. In your Shopify Admin, go to Settings > Shipping and delivery.
2. Open a shipping profile (for example, General shipping rates).
3. In the Products section, review the list of assigned products and variants.

• If the product or variant is listed, it is assigned to that shipping profile.
• If it is not listed, check your other custom shipping profiles.
• Also, review the General shipping rates profile if you’re using multiple profiles.

If the product does not appear in any shipping profile, it is not assigned to one. This can block bundle purchases and may cause the bundle to appear unavailable.

How to add a product to an Existing Shipping Profile

Step 1: Open shipping settings

• In your Shopify Admin, go to Settings > Shipping and delivery.
• Select the shipping profile you would like the product to be assigned to.

Step 2: Add the product

• In the Products section of the shipping profile, click Add products.
• Search for and select the product (or specific variants, if needed).
• Click Done, then Save to apply the changes.

Step 3: Confirm fulfillment locations

• After adding the product, make sure the correct fulfillment location is included in the shipping profile:
• Scroll to the Fulfillment locations section.
• If the location assigned to your bundle is not listed, click Add locations and select the appropriate one.

Shipping profiles are location-based, so the correct fulfillment location must be included for the bundle to be available for purchase.

4. A third-party app is overriding inventory

Simple Bundles does not integrate with an external inventory management app unless inventory for bundle components is updated directly in Shopify. For accurate inventory syncing, ensure that both the parent bundle SKU and all component SKUs are set to track inventory in Shopify. You can confirm this by exporting your bundles and reviewing the inventory_management column. For assistance, here’s a guide on bulk exporting your bundles to easily check and update your bundle inventory. Bulk exporting bundle data.

If you’re using multiple locations along with an app-based 3PL, you may notice that bundles suddenly appear out of stock, even though the component products still have available inventory.

This typically happens because, by default, Simple Bundles can’t sync inventory with app-managed locations. Some fulfillment apps create locations with the inventoryManagement  flag set to true     . When this flag is enabled, Shopify restricts inventory updates so that only the fulfillment app itself can manage inventory at that location. As a result, external apps like Simple Bundles are unable to update stock levels there. You can find more details about this Shopify limitation here.

Solution: Ask your 3PL to disable the inventoryManagementflag

The cleanest fix is to contact your fulfillment or 3PL app and ask whether they can set the inventoryManagement flag to false at their managed location. This allows Simple Bundles to read and sync inventory there correctly. Not all fulfillment apps support this, as it may affect their own internal workflows.

If your 3PL is unable or unwilling/cannot to switch off the inventoryManagementflag, here are workarounds to keep your bundles purchasable:

• Turn off Track quantity on the parent bundle variant or enable Sell when out of stock on the parent bundle. This keeps your bundle visible and purchasable on the storefront, while your actual stock protection continues to happen at the component level via Cart Transform. If a customer tries to order more than what's available, checkout will still catch it and prevent overselling.

Note: With this workaround, customers won't see a "sold out" indicator directly on the product page. The bundle will always appear available on the storefront since there's no live inventory number for Shopify to check against. Customers will only be blocked if they try to check out with more than the available quantity.

If seeing accurate sold-out status directly on the product page (rather than only at checkout) is important for your store, reach out to our support team. This isn't a built-in app setting, but our technical team can review your specific setup and advise on a custom solution for your theme.

5. Empty bundle created from an existing product

If you used an existing Shopify product with inventory as the bundle parent, but it appears empty in the Simple Bundles app (no components assigned), this can cause inventory mismatches. Simple Bundles may not correctly calculate stock for a bundle without components.

Solution: If you have an empty bundle, remove it from the Simple Bundles app. The product will continue to function as a regular Shopify product.

Bundle options showing as 'Unavailable'? Here's what that means and how to fix it

When a bundle option appears as “Unavailable” on your storefront (instead of “Sold out”), it usually means that the specific product variant doesn’t exist or isn’t supported by your store theme. This can happen for two main reasons:

1. Missing variant in Shopify

If the specific combination of variants hasn’t been created in the Shopify product. You can check by opening the product in Shopify and confirming whether the variant exists. If not, you can create it manually.

2. Theme limitation (Over 100 Variants)

Even if the variant exists, your theme may not support displaying it, especially if your product has more than 100 variants. While Shopify and Simple Bundles support over 100 variants, not all themes do. Consult your theme developer to extend variant support or consider switching to Infinite Options Bundles, which work around Shopify’s variant limits. Refer to this Shopify help guide: Considerations for adding variants

When to use “Continue selling when out of stock”

Shopify’s “Continue selling when out of stock” setting overrides Simple Bundles’ inventory check and allows bundles to be purchased even when a component is at 0. Use this setting carefully.

How to run a manual inventory sync

If you’ve restocked a component but the bundle still shows as out of stock, run a manual sync:

1.     Go to Simple Bundles → Settings

2.     Click Resync all bundle quantities

3.     Wait a few moments for the sync to complete

The bundle inventory will recalculate based on the lowest available component stock at the fulfillment location.

Still seeing issues?

Contact Simple Bundles support at hello@simplebundles.io, and we’ll be happy to help!