Send seller-fulfilled Amazon and Walmart orders to a 3PL, with tracking back on time
Updated · By Ecomsellertool editorial team
To send seller-fulfilled Amazon and Walmart orders to a 3PL automatically, pull new orders from each marketplace's Orders API, acknowledge Walmart orders, and pass each order to the 3PL with its ship-by date. When the 3PL ships, confirm the shipment with the carrier and tracking number before that date. Check for cancellations right before the 3PL picks, and watch late shipment and valid tracking rates.
- Amazon deprecated the Orders API v0 order-reading operations, including getOrders, on January 28, 2026 and removes them on March 27, 2027; searchOrders in v2026-01-01 replaces getOrders (checked October 13, 2026).
- Amazon's confirmShipment stays in Orders API v0; each package needs a carrier code, tracking number, ship date and order items.
- Walmart says acknowledging an order is a required step before shipping; Ship Order Lines then records the carrier and tracking and captures the customer's payment.
- Walmart counts an order as late when it is marked shipped, or first scanned by the carrier, after the Expected Ship Date; the standard is a Late Shipment Rate of 5% or below.
- Walmart's seller performance standards also ask for valid tracking of 99% or above and cancellations of 2% or below, over the last 30 or 60 days.
The step map: who runs each step
Trigger: A new seller-fulfilled order appears on Amazon or Walmart, found by a scheduled pull every few minutes and, where set up, a marketplace notification; a second schedule checks open orders against their ship-by dates.
| Step | What happens | Who runs it |
|---|---|---|
| 1 | Pull new seller-fulfilled orders from each marketplace: Amazon's searchOrders filtered to merchant-fulfilled, unshipped orders, and Walmart's All released orders call. Store each order once, keyed by its marketplace order ID. | Rule |
| 2 | Acknowledge each Walmart order, then map every line to your SKU and the 3PL's item code. An order with an unknown SKU, a missing address field or a quantity above stock goes to the exception queue instead of the 3PL. | Rule |
| 3 | Send the order to the 3PL with the ship-by date, the shipping service the buyer paid for and a channel tag, so the warehouse can pick by deadline and pack Walmart orders in plain boxes. | Rule |
| 4 | Right before the 3PL's pick wave, check each order again for a buyer cancellation request or a cancelled status, and ask the 3PL to stop any order that changed. | Rule |
| 5 | A person works the exception queue: fixes SKU maps and addresses, decides whether to cancel an order that cannot ship, and answers buyer cancellation requests. | Person |
| 6 | When the 3PL ships, confirm the shipment on the marketplace with the carrier, tracking number, ship date and lines: confirmShipment on Amazon, Ship Order Lines on Walmart. A rejected confirmation raises an alert with the marketplace's error. | Rule |
| 7 | A deadline check lists every order that is still unshipped a few hours before its ship-by date, and every confirmed order whose carrier shows no first scan by the next morning. | Rule |
6 rule steps · 0 AI model steps · 1 person step. A rule follows fixed logic you approve; an AI model handles messy input and its output is checked by rules; a person makes the calls listed below.
What stays with a person
- Orders the rules cannot place: unknown SKUs, addresses that fail the check, quantities above stock
- Seller cancellations and refunds, which cost an order and count against your cancellation rate
- Buyer cancellation requests on orders the 3PL may already have picked
- Orders still unshipped close to their ship-by date, and confirmed orders with no first carrier scan
- Changes to the SKU map, the 3PL cut-off times and which orders go to MCF or WFS instead
Which tools can run it
- Your 3PL's own marketplace connector or a shipping platform that imports Amazon and Walmart orders, for one 3PL and simple orders
- Zapier, Make or n8n calling both marketplace APIs and the 3PL's API, for modest volume, with a log of every run
- Custom code on your accounts, for several 3PLs, cancellation checks before each pick wave, ship-by alerts and Amazon's move to searchOrders
Systems it connects
- Amazon SP-API: Orders, Feeds, Notifications, Reports
- Walmart Marketplace Orders API
- 3PL API, portal or file drop
- Carrier tracking
- SKU map
- Slack or email for the exception queue
Build size: Medium
Each call is simple; the work is two marketplaces with different rules, the deadline clock and catching cancellations before the warehouse picks.
A brand that ships its own Amazon and Walmart orders from a 3PL lives on two clocks it does not set. Each order arrives with a ship-by date, and each marketplace scores you on whether the shipment was confirmed, with valid tracking, before that date. The 3PL only sees what you send it. This recipe covers the marketplace side of that handoff: pulling orders, acknowledging them, passing the deadline to the warehouse, catching cancellations and confirming tracking back. It assumes these orders do not go through Amazon MCF or Walmart WFS. It is one page of our automation library.
How do Amazon and Walmart hand a seller-fulfilled order to you?
Through two APIs that do the same job in different ways. The table puts them side by side, one row per step, with the operation names from each marketplace's documentation (checked October 13, 2026). Use it as the spec for your integration or as the checklist for a 3PL connector you are about to buy.
| Step | Amazon (Selling Partner API) | Walmart (Marketplace Orders API) |
|---|---|---|
| Fetch new orders | searchOrders (Orders API v2026-01-01) with fulfilledBy=MERCHANT and fulfillmentStatuses=UNSHIPPED, up to 100 orders a page. The v0 getOrders is deprecated and is removed on March 27, 2027 | All released orders, GET /v3/orders/released: lines in Created status, ready for you to fulfill. Seller-fulfilled by default, up to 200 a page, orders from the last 180 days |
| Acknowledge | No acknowledge call in the Orders API. The Order Acknowledgement feed, POST_ORDER_ACKNOWLEDGEMENT_DATA, "acknowledges or cancels an order" | Acknowledge Orders, POST /v3/orders/{purchaseOrderId}/acknowledge, for the whole order. Walmart calls it a required step before shipping |
| Ship-by date | fulfillment.shipByWindow.latestDateTime, returned with includedData=FULFILLMENT (v0: LatestShipDate) | shippingInfo.estimatedShipDate, in Unix epoch time; Walmart's metrics call it the Expected Ship Date |
| Confirm shipment | confirmShipment (Orders API v0), one package at a time: carrier code (required in all marketplaces), tracking number, ship date and order items. The POST_ORDER_FULFILLMENT_DATA feed does the same in bulk | Ship Order Lines, POST /v3/orders/{purchaseOrderId}/shipping: carrier name (or another carrier plus a tracking URL), method code, ship time and tracking number. It also captures the customer's payment |
| Buyer cancellation | The ORDER_CHANGE notification reports buyer-requested cancellations; searchOrders with includedData=CANCELLATION shows the request and its reason | You cancel the lines with Cancel Order Lines and the reason CUSTOMER_REQUESTED_SELLER_TO_CANCEL |
| Seller cancel or refund | Cancel through the Order Acknowledgement feed; refund through the Order Adjustments feed, POST_PAYMENT_ADJUSTMENT_DATA | Cancel Order Lines, POST /v3/orders/{purchaseOrderId}/cancel, with a reason such as SELLER_CANCEL_OUT_OF_STOCK; Refund Order Lines, POST /v3/orders/{purchaseOrderId}/refund |
| Rate limits and polling | searchOrders: 0.0056 requests a second with a burst of 20, roughly one call every three minutes once the burst is spent. getOrder: 0.5 a second; confirmShipment: 2 a second. Limits apply per account and application | All released orders: 60 a minute. Acknowledge, ship, cancel and refund: 60 a minute each. Notifications (webhooks) cut how often you need to poll |
| Account-health metric at risk | Late shipment rate, valid tracking rate and pre-fulfillment cancellation rate, each shown against a target in Account Health | Late Shipment Rate at or below 5%, Valid Tracking Rate at or above 99%, Cancellation Rate at or below 2% |
Three rows decide most of the build. The fetch row on Amazon is changing: Amazon's deprecation schedule lists getOrders, getOrder, getOrderItems and three buyer and address calls in Orders v0 as deprecated on January 28, 2026, with removal on March 27, 2027 (checked October 13, 2026). Amazon's Orders API page calls v2026-01-01 the current version, and its migration guide maps getOrders to searchOrders and LatestShipDate to the ship-by window. Any connector still reading orders through v0 needs that change before March 2027.
The confirm row stays where it was. The deprecation entry does not list confirmShipment, which is still part of Orders v0. Amazon's published v0 model makes the package reference, carrier code, tracking number, ship date and order items required, and says the carrier code is required for all marketplaces (checked October 13, 2026). The v2026-01-01 model adds the fulfilledBy and fulfillmentStatuses filters used in the fetch row.
The acknowledge row is the one most often missed on Walmart. Walmart's guide to choosing an Orders API says acknowledgement confirms you received the order and intend to fulfill it, and calls it "a required step before shipping" (checked October 13, 2026). Its Orders Management API overview describes the line statuses an integration should track: Created, Acknowledged, Shipped and Canceled. The detail for each call is in Walmart's reference for All released orders, Acknowledge Orders, Ship Order Lines and Cancel Order Lines (all checked October 13, 2026).
What does the 3PL need from you?
A 3PL can only ship on time if every order arrives with the facts it needs to pick by deadline and pack to each marketplace's rules. Send this with each order, or agree it once in writing:
- The marketplace order ID, a channel tag (Amazon or Walmart) and, for Walmart, the line numbers you will confirm against
- The ship-by date and time, converted to the 3PL's time zone, next to the order date
- The shipping service the buyer paid for, mapped to a carrier service the 3PL can buy
- Your SKU and the 3PL's item code for every line, from one SKU map you own
- Packaging rules per channel. Walmart's packaging policy prohibits seller-branded boxes, promotional material and other retailers' packaging, and gives a nonbranded box in a neutral color as the allowed example (checked October 13, 2026)
- The daily pick cut-off and carrier pickup times, so orders arriving after the cut-off are flagged against their ship-by date
- How the 3PL returns tracking: carrier name as each marketplace spells it, tracking number, ship time and which lines are in which package
- A way to stop an order: a cancel call or a contact who answers before the next pick wave
The carrier name is the field that breaks most often. Amazon wants a carrier code and Walmart a carrier name from its own list, so the 3PL's "UPS Ground" has to become each marketplace's value before the confirmation goes out. Keep that mapping in the integration, not in the warehouse.
How should the order flow run, step by step?
Pull, check, acknowledge, send, recheck, confirm. On Amazon, pull with searchOrders and a lastUpdatedAfter time, which catches new orders and status changes in one call. At the default rate of 0.0056 requests a second (checked October 13, 2026), a pull every five minutes leaves room for the burst when there are several pages. On Walmart, pull released orders every few minutes; Walmart's rate limiting page allows 60 calls a minute for that endpoint, and its notifications overview says webhooks for events such as a new order reduce how often an application must poll (both checked October 13, 2026).
Before anything reaches the 3PL, rules check the order: every SKU mapped, the address complete, enough stock at that warehouse. A Walmart order that passes is acknowledged at once; one that fails goes to the exception queue with the reason. To take an illustrative example, not a client result: a brand shipping 80 seller-fulfilled orders a day that adds a new listing may see its first orders for it stop as unmapped SKUs. The person who fixes the map releases the order, and it still reaches the 3PL before the cut-off.
The confirmation runs the other way. When the 3PL reports a shipment, the integration translates the carrier, splits the lines into packages and calls confirmShipment or Ship Order Lines. A rejected call is not a warning to read later: until it succeeds, the marketplace thinks the order has not shipped, and the ship-by clock keeps running.
How do cancellations reach the warehouse in time?
By checking twice. Amazon's notification types say ORDER_CHANGE is sent for important changes, including order status changes and buyer-requested cancellations (checked October 13, 2026). Subscribe to it and act on it, but also re-read every open order right before each pick wave, because a notification can arrive late or not at all. An order the buyer asked to cancel should not be picked.
Cancelling is a decision, not a rule. On Amazon, the order feed types cover it: the Order Acknowledgement feed "acknowledges or cancels an order", and the Order Adjustments feed "issues a refund adjustment for an order" (checked October 13, 2026). On Walmart, Cancel Order Lines takes a reason, and Walmart's reference warns that the fraud reason must not be used for orders that are not fraudulent. Every seller cancellation counts against your cancellation rate, so the workflow drafts it with the reason and a person sends it.
Which metrics show the handoff is working?
The late shipment and valid tracking rates, on both marketplaces. Walmart's Late Shipment Rate guide counts an order as late when it is marked shipped after the Expected Ship Date or first scanned by the carrier after it, and says a missing or invalid first scan cannot be verified as on time (checked October 13, 2026). Walmart's seller performance standards ask for a Late Shipment Rate of 5% or below, Valid Tracking of 99% or above, Cancellations of 2% or below and On-Time Delivery of 90% or above, over the last 30 or 60 days, and say missing them may lead to suppression, suspension or termination (checked October 13, 2026).
On Amazon, the seller performance report, GET_V2_SELLER_PERFORMANCE_REPORT, returns the Account Health metrics, including late shipment rate, valid tracking rate and pre-fulfillment cancellation rate, each with a target value (checked October 13, 2026). Pull it weekly and split the misses by 3PL and carrier. A late order with a label bought on time usually means a missed pickup, and that is a conversation with the warehouse, not a code fix.
When should these orders go through MCF or WFS instead?
When the 3PL cannot meet the deadline at a sensible cost. Amazon MCF and Walmart WFS take the shipping off your hands, but each has its own stock pool, packaging rules and fees. Our MCF vs WFS vs 3PL guide compares the three for each channel, and the order routing page covers choosing a node for each order by stock, cost and ship-by date. If your Shopify orders go to the same 3PL, the Shopify orders to a 3PL recipe covers the hold and cut-off rules on that side.
Check the connection too. Walmart's Delegated Access notice says existing Delegated Access keys work until April 30, 2027 (checked October 13, 2026). A 3PL connector still on one will stop pulling Walmart orders then; our Walmart OAuth migration guide covers the reconnection, and the Walmart Marketplace API integration page lists the areas we have built. Amazon connections authorize through the SP-API on your own Seller Central account.
Who builds marketplace-to-3PL automation?
Ecomsellertool builds the order handoff on your own Amazon, Walmart and 3PL accounts: the order pull, Walmart acknowledgement, the SKU map, cancellation checks before each pick, tracking confirmation and ship-by alerts. We have built software on Amazon's seller APIs since 2017 and shipped 50+ tools for 100+ teams. Send a project brief or read how our workflow automation service works.
The pieces are work we have shipped:
- Amazon order and shipment flows inside a warehouse system. For EzBookPrep, a book prep business serving Amazon sellers, we built a system that runs Amazon's inbound and outbound shipment flow through its APIs, pulls inventory and order reports in automatically, and sends alerts for the next action on each book, replacing the manual follow-ups that had made the owner the bottleneck.
- Rules that run within Amazon's processing limits, with a log. TRAKTOR, rule-based automation we built for ad campaigns, staggers its data fetching to work within Amazon's processing times and records every change it makes in an action log. The same habits keep an order pull inside its rate limits and leave a record of every confirmation.
The integration can run on Ecomsellertool Growth OS beside your other order flows.
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Describe the workflow you want automated. We reply with a written plan: scope, timeline and a fixed price.
Frequently asked questions
How do I send Amazon seller-fulfilled orders to my 3PL automatically?
Read new merchant-fulfilled orders from Amazon's Orders API, send each one to the 3PL with its latest ship date, and confirm the shipment back to Amazon with the carrier code and tracking number when the 3PL ships. Amazon is replacing getOrders with searchOrders, so build new integrations on the 2026-01-01 version. Many 3PLs also offer their own Amazon connector.
Do I have to acknowledge Walmart orders before my 3PL ships them?
Yes. Walmart's developer documentation calls acknowledging an order a required step before shipping. Acknowledge the purchase order through the Acknowledge Orders call as soon as you have checked it, then send it to the 3PL, and mark it shipped with Ship Order Lines once the 3PL has the tracking number.
Which date does my 3PL need to ship Amazon and Walmart orders by?
The marketplace's own ship-by date, not the delivery date. On Amazon it is the latest date in the order's ship-by window, called LatestShipDate in the old API. On Walmart it is the estimated ship date in the order's shipping info, which Walmart's metrics call the Expected Ship Date. Send that date to the 3PL with every order.
Why do my Walmart orders count as late when the 3PL shipped on time?
Walmart counts the carrier's first scan, not the label. An order is late if it is marked shipped after the Expected Ship Date, if its first carrier scan comes after that date, or if the first scan is missing or invalid. A label printed on time for a parcel that misses the day's pickup still counts as late.
What happens if a buyer cancels after the order went to the 3PL?
On Amazon, a buyer cancellation request arrives as an order change, which the ORDER_CHANGE notification reports and the order data shows. On Walmart, you cancel the lines yourself with a reason such as customer requested. Either way, ask the 3PL to stop the order before it picks, and check every open order again right before each pick wave.
Should I use Amazon MCF or Walmart WFS instead of a 3PL for these orders?
Sometimes. MCF and WFS take the shipping and some of the performance risk, but they ship unbranded and from separate stock pools. A 3PL keeps one pool and your packaging, and you carry the deadlines yourself. Our MCF vs WFS vs 3PL guide compares the three, and the order routing page covers picking a node per order.
