Shipping a PO to Amazon as a Vendor: Routing Requests, Carrier Central, and ASNs

You have an accepted purchase order and a ship window, and now the freight has to reach the fulfillment center inside it. Vendor Central doesn't lay out what happens next in one place: the routing request lives in Vendor Central, the delivery appointment lives in Carrier Central on a separate login, and the ASN can come from Vendor Central or from your EDI feed. Which of those you touch, and in what order, depends on one term on the PO: who pays for freight.

This guide runs the sequence in order, from a confirmed PO to a received shipment. The mechanics come from Amazon's North American Vendor Shipment Preparation and Transportation Manual. That manual was last updated on September 1, 2016, and it is still the copy Amazon hosts publicly, so treat its menu paths as a starting point and check them against your own account. Where Amazon has changed a rule since, most importantly pallet labeling in July 2024, the section says so.

Start with the freight terms on the PO

Every PO ships on one of two freight terms, and the manual names each of them two ways.

• Collect (WePay). Amazon arranges and pays for the freight. You submit a routing request in Vendor Central, Amazon assigns the carrier, and that carrier comes to your dock. On truckload and LTL freight, the assigned carrier also books the delivery appointment at the fulfillment center.
• Prepaid (TheyPay). You arrange and pay for the freight. There is no routing request. Your carrier requests the delivery appointment in Carrier Central, and making sure it lands inside the PO's delivery window is your responsibility.

That makes the routing request and the Carrier Central appointment separate steps, booked by different parties in different portals. On Collect, your booking work ends once the routing request is in and the carrier picks up. On Prepaid you never see a routing request, but you do have to manage the carrier who books the appointment.

Both paths meet again at the ASN and the labels. Amazon requires an ASN for every shipment regardless of size or freight terms, and every carton needs a compliant label either way. Small parcel follows the same split with one difference: Collect small parcel still needs a routing request, while Carrier Central appointments apply to LTL and truckload only.

Confirm the PO first

The shipping sequence starts once the PO is acknowledged, and the manual gives you one day from the order date to accept, reject, or backorder it. The ship or delivery window in the PO header belongs to Amazon, and updating your expected ship date or expected delivery date does not move it. Ship exactly the items and quantities you confirmed, because units beyond the confirmed quantity draw an Overage chargeback. The purchase order glossary entry defines the document, and the inventory management guide covers what confirmation does to fill rate and forecasts.

Collect path: submit the routing request

A routing request tells Amazon that freight is ready to be picked up from your location. Amazon uses it to pick the shipping method and the carrier, so the numbers you enter decide what truck shows up.

1. Open the Shipments tool under the Orders tab in Vendor Central. If you do not see Shipments under Orders, a Vendor Central administrator on your account has to grant you access.
2. Add every PO going to the same fulfillment center to one request. You cannot add a PO to a request after it has been submitted, so a late PO needs its own routing request.
3. Enter accurate pallet count, carton count, weight, and cube. Non-palletized freight goes in with a pallet count of zero.
4. Set a Freight Ready Date inside the PO's ship window, and plan to have the freight ready to load by 8 AM local time on that date unless you ship on a predefined milk run lane.
5. Enter the bill of lading number. If you do not have one yet, use a unique internal reference such as an order or invoice number, then put the real BOL number in the ASN and give it to the carrier.
6. Submit inside the timing window. The manual says no sooner than 7 days before the Freight Ready Date, but as soon as you know the freight details and that date, and at least one day ahead. A same-day Freight Ready Date is not allowed unless you ship on a predefined milk run. For a Wednesday Freight Ready Date, the request has to be in before 11:59 PM PST on Tuesday.

What comes back. Amazon starts processing routing requests at 12 AM PST on the Freight Ready Date and emails tender details to you and the assigned carrier by 5 AM PST (2 PM PST for milk runs). The response includes the carrier's contact information. If a load is not assigned, Amazon may be looking to consolidate it, which can take two business days. Routing also generates the ARN (Amazon Reference Number), which exists only for Collect shipments and has to appear on your BOL and your ASN.

Pickup. An LTL carrier contacts you within one business day and gives a two-hour pickup window. A truckload carrier first secures the delivery appointment at the fulfillment center, then calls to schedule the pickup. Before you hand freight to anyone, confirm it is the assigned carrier and that it has a valid ARN.

Carrier choice. A Collect vendor may never pick its own carrier. Shipping with anyone other than the assigned carrier results in a chargeback and can delay delivery. You can edit or delete a routing request until it is tendered; after that, changes go through Contact Us with Shipments as the support topic.

Prepaid path: your carrier books Carrier Central

Carrier Central is Amazon's appointment portal for inbound freight at carriercentral.amazon.com, on its own login separate from Vendor Central. The 2016 manual calls it CARP, the Carrier Appointment Request Portal, so older SOPs and third-party docs use that name for the same step.

1. Choose the carrier. Amazon strongly recommends its preferred carriers and lists their contacts in the Vendor Central Resource Center under Operations.
2. Confirm the carrier has a valid SCAC before it requests a Carrier Central account. The carrier requests its own account; a request you submit on its behalf will be denied.
3. Give the carrier the complete list of PO numbers, the PRO number, and the BOL information, because Amazon asks for all three when the appointment is scheduled. Give it accurate pallet, carton, and unit counts to enter as well.
4. Have the carrier request the appointment at least 24 hours before the desired delivery date, with a specific date and time, inside the PO's delivery window.
5. If the appointment moves or is cancelled, rebook it at least 24 hours before the originally planned delivery. A later rebooking pushes the delivery date out.
6. At the dock, the carrier presents the appointment number (the ISA number) and a printed BOL that meets Amazon's requirements.

The fulfillment center accepts nothing without a scheduled appointment, and a truck that arrives without one can be turned away or held for hours. An appointment missed by 30 minutes or more is refused, a chargeback fee may be assessed, and the carrier has to request a new appointment.

Build the ASN

The ASN tells Amazon what is on the truck before it arrives. Amazon matches your ASN to the carrier's own shipment notice using the ARN, PRO, and BOL, so those numbers have to agree with what the carrier holds. The ASN glossary entry covers the definition; this is what goes in it.

• ARN: required on Collect truckload and LTL shipments.
• PRO number: required on every shipment, issued by the carrier, and unchangeable in transit. Multi-box small parcel shipments need a tracking number per carton. Get the PRO from the carrier before you send the ASN.
• BOL number: required on an EDI ASN, optional on a Vendor Central ASN.
• SCAC for the carrier.
• Every PO on the shipment, with line items using the right identifier.
• Quantities of units, cartons, and pallets that match what you confirmed on the PO. Overstated quantities lead to chargebacks.
• Weight and volume of the shipment.
• Expiration date and lot number for perishable goods.
• Carton SSCCs if you send the ASN by EDI.

EDI-enabled vendors send the EDI 856 and should use Vendor Central's manual ASN only during an EDI outage. Everyone else builds it in Vendor Central under Orders, then Shipments. The Amazon EDI guide covers the 856 alongside the other documents.

Timing. The ASN must reach Amazon within 30 minutes of the truck leaving your warehouse or at least 6 hours before the fulfillment center appointment, whichever comes first. If the fulfillment center is close to your dock, the manual recommends sending it before the trailer departs.

Corrections. An ASN cannot be deleted or cancelled. You can edit it for 7 days from submission or until the shipment arrives, whichever comes first, through the EDI 856 or Vendor Central's ASN edit feature.

Label the cartons and pallets

Every carton needs a barcode that carries its contents, in one of four formats, and your ASN method decides which one you use.

• SSCC (Serial Shipping Container Code): for EDI 856 vendors on the 5010 version, any carton count. Each SSCC is purchased from GS1 and unique to one carton, and it's listed in the ASN at carton level. An EDI vendor must not use AMZNCC.
• AMZNCC (Amazon Container Code): for vendors who submit ASNs in Vendor Central, on shipments under 250 cartons. You enter item detail for each carton in the Shipments workflow, and Vendor Central generates the label to print.
• BPS (barcode packing slip): EDI or non-EDI, for a 2D data string under 1,600 characters.
• GTIN-14: case-level product barcodes registered with Amazon, with extra ASN conditions.

A carton without a compliant label draws a No Carton Content Label chargeback, which the 2016 manual sets at $5 per carton for US vendors. A carton whose SSCC disagrees with the ASN that declared it is also an ASN accuracy problem, so a single bad label can draw both chargebacks. The SSCC label entry explains the barcode itself.

Pallets are where the 2016 manual is out of date. Its pallet section asks for a pallet label with the pallet number, BOL, PRO, PO numbers, and the SKU or a "Mixed SKU" marking, and treats a pallet SSCC as something vendors should provide on single-ASIN pallets. Since July 1, 2024, Amazon requires every pallet, single-SKU and mixed-SKU, to carry its own license-plate barcode, either an SSCC or an AMZNCC. On LTL and truckload freight that means a pallet label on each pallet plus a label on each carton, since the pallet barcode does not replace carton labels. Parcel shipments are unchanged at one label per carton. Vendors sending the ASN by EDI or API provide the pallet license plate at the tare level, so the ASN maps cartons to the pallet they sit on. Floor-loaded single-SKU cartons also can no longer rely on a GTIN-14 alone.

If your labeling template was built from the manual, mixed-SKU pallets are the gap to close first.

What each step turns into if you miss it

Each failure has a name in Amazon's chargeback categories. The chargebacks guide lists all seven families, and the dispute guide covers contesting one.

• Shipping outside the window: a PO on-time infraction. See PO On-Time Accuracy.
• Shipping more than you confirmed: Overage.
• Collect freight on your own carrier: a chargeback and a possible delivery delay.
• No appointment, or 30 or more minutes late to it: freight refused and a possible chargeback fee. The inventory management guide covers No Show with the other shipping-window chargebacks.
• Late, missing, or wrong ASN: ASN chargebacks, including ASN Accuracy.
• Missing or wrong carton label: No Carton Content Label, and ASN Accuracy if the label and ASN disagree.
• A BOL missing required fields: the shipment is refused on delivery.

What Vendor Central will not give you

The steps above run across systems that don't share a screen. Carrier Central sits on its own login, so lining up the appointment your carrier booked with the ASN you submitted is a manual check. The Shipments history the manual describes covers the last 10 or 90 days. And the public manual still dates from 2016, so rule changes like the 2024 pallet requirement arrive as help pages you have to find and fold into your own process.

Mistakes anywhere in this sequence surface later in your receive fill rate and on-time performance. InsightLeap puts product-level Vendor Central PO data next to sales and inventory, so you can see which ASINs a run of short or late receipts is hitting.

Before the next PO ships, check its freight terms first, because they decide whether you're filing a routing request or relying on your carrier's appointment. The ASN deadline and the pallet license-plate labels apply on both paths.