Yes. Both modes can be active simultaneously. WFS handles Walmart.com orders flowing into Shopify, while MCS handles Shopify orders going out to Walmart warehouses for fulfillment. They operate independently and are configured separately in Settings.

Why is my Shopify order not being sent to Walmart?

The most common reasons:

MCS is disabled — check Settings → Settings tab → the "Create Walmart MCS orders from Shopify" toggle
No fulfillment request was submitted — if you are using "Wait for fulfillment request" mode, Shopify must explicitly submit a fulfillment request to the Walmart Fulfillment Services location. Set up Shopify Flow or enable auto-fulfill in Shopify Checkout settings. See Configuring Order Fulfillment.
Unmapped SKUs — check the Orders page for an EXCEPTION status and see which variant IDs need mapping
No Channel ID — the Global MCS Sales Channel ID must be set in Settings → Walmart Account tab

What is the difference between "Wait for fulfillment request" and "Auto-process when paid"?

In Wait for fulfillment request mode, the app sits idle until Shopify's fulfillment order system submits a request to your Walmart Fulfillment Services location. This happens via Shopify Flow automation, Shopify's auto-fulfill setting, or a manual click on the order.

In Auto-process when paid mode, the app bypasses the fulfillment request step entirely. As soon as Shopify confirms the order is paid, the app submits it directly to Walmart MCS. This requires no Shopify Flow setup but gives you less control over individual orders.

What happens when a Shopify order is cancelled?

If the order has not yet been submitted to Walmart, it is marked CANCELLED in the app immediately with no Walmart API call needed.

If the order was already submitted to Walmart (it has a Walmart MCS order ID), the app sends a cancellation request to Walmart. The cancellation applies to the entire order. If Walmart has already shipped the order, the cancellation will be rejected and the order remains in its current status.

What is an ON_HOLD order?

Some sales channels (like TikTok Shop or Amazon) place a hold on orders before they are ready for fulfillment — for example, during a fraud review window. The app tracks this status. Once the hold is released, the order resumes processing automatically.

How quickly does tracking information appear in Shopify?

After Walmart marks an order as SHIPPED, the app fetches the tracking number during the next status poll and writes it back to the Shopify order. This typically happens within 15 minutes of Walmart updating the status. You can also click Sync on the order in the app to fetch the latest status immediately.

Will Walmart.com customers receive a shipping notification?

When a WFS order (Walmart.com → Shopify) is synced, Walmart has already sent the customer a shipping notification directly. The Shopify order created by the app is for your records and does not trigger additional Shopify email notifications to the customer.

For MCS orders (Shopify → Walmart), Shopify handles the shipping notification to the customer when the fulfillment is completed.

Can I manually trigger an order to sync?

Yes. On the Orders page, click Sync next to any order that has a Walmart order ID. This immediately fetches the latest status from Walmart and updates the record. For EXCEPTION orders with no Walmart ID, use the Retry button instead after resolving the underlying issue.