Amazon Vendor Central EDI: What 1P Suppliers Need to Know

Before anything else, figure out which Amazon program you’re actually in — because the two paths have nothing in common technically, and suppliers routinely search for "Amazon EDI" without realizing they may not need it at all.

1P (First-Party / Vendor Central): Amazon buys your product wholesale at a negotiated cost, resells it at their chosen price, and owns the inventory once it ships to their fulfillment centers. You invoice Amazon. You receive purchase orders from Amazon. This relationship runs on traditional EDI — the same AS2-transmitted, standardized document exchange you’d use with Walmart or Target. If you’re in Vendor Central, you need EDI.

3P (Third-Party / Seller Central): You sell directly to consumers on Amazon’s marketplace. You set the price, you hold inventory (or use FBA), and Amazon takes a referral fee. This relationship runs on Amazon’s Selling Partner API (SP-API) — web-based API calls, not EDI. If you’re in Seller Central, you don’t need EDI for Amazon.

This post is for 1P suppliers. If you’re not sure which you’re in, check your Amazon dashboard. For the retailers we support, see our trading partners page: Vendor Central (vendorcentral.amazon.com) means 1P; Seller Central (sellercentral.amazon.com) means 3P.

Vendor Central Transaction Sets

Amazon’s Vendor Central EDI uses a tight set of transaction sets, and each one feeds a specific automated process at Amazon’s fulfillment centers:

• EDI 850 — Purchase Order: Amazon sends you a wholesale PO. This is the trigger for your fulfillment cycle.
• EDI 855 — Purchase Order Acknowledgment: You confirm receipt within 24 hours and flag any changes — quantities you can’t fulfill, items discontinued, requested date adjustments. Amazon uses this acknowledgment to update their inventory planning; if you don’t send it within the window, Amazon treats the PO as unacknowledged and may escalate or reroute the order.
• EDI 856 — Advance Ship Notice (ASN): The most critical document in Amazon’s EDI flow. Amazon’s fulfillment centers use the ASN to drive automated receiving — when your truck arrives, their systems expect to match each carton to pre-loaded ASN data by scanning its barcode, without human intervention. If the ASN is missing, wrong, or late, the shipment gets pulled from the automated line and placed in a manual receiving queue. That means receiving delays, missed inventory availability windows, and chargebacks.
• EDI 810 — Invoice: Required for payment. Amazon’s payment system matches the invoice against the original PO and the received ASN; any discrepancy holds up payment and can trigger a deduction.

Connection: AS2 Only

Amazon requires AS2 (Applicability Statement 2) for Vendor Central EDI — a direct, encrypted, certificate-based connection between your system and Amazon’s EDI endpoint. No VAN (Value-Added Network) option. This means you need an AS2 server that’s always available, with digital certificates installed and renewed on schedule, or a managed EDI provider maintaining that connection. If your AS2 connection drops during a transmission window, documents don’t get queued at an intermediary — they fail, and you need to know about it immediately.

ASN Requirements: What Makes Amazon Different

Amazon’s 856 requirements are among the strictest in retail, and they’re strict because their receiving process is almost entirely automated:

• Every carton must have a unique SSCC-18 barcode — the Serial Shipping Container Code is what the fulfillment center scanner reads to match the physical carton to the ASN data. Duplicate or missing SSCC-18s break the match.
• All items in a carton must be individually identified — Amazon needs item-level pack structure in the ASN, not just carton counts. If a carton contains three different SKUs, all three must appear in the 856 with correct quantities.
• ASN must be sent before the shipment arrives at the FC — Amazon’s receiving dock expects the ASN data to be pre-loaded. A shipment that arrives before its ASN goes into manual handling, which delays inventory availability and triggers compliance deductions.

Amazon’s Operational Performance Program (OPP)

Amazon tracks vendor performance through the Operational Performance Program, and unlike some retailers where compliance metrics are somewhat opaque, Amazon surfaces these metrics directly in Vendor Central. Three categories matter most:

PO Confirmation Rate — the percentage of 850s you acknowledge with an 855 within the required 24-hour window. Fall below Amazon’s threshold and you’ll see automatic deductions on your invoices. But the deeper consequence is buyer behavior: Amazon’s retail teams use PO Confirmation Rate as a signal of supplier reliability. Suppliers with consistently low confirmation rates may see reduced PO volume — Amazon’s automated purchasing systems deprioritize vendors who don’t acknowledge reliably, which means fewer orders without anyone explicitly telling you you’ve been deprioritized.

Ship Confirmation Rate — the percentage of shipments for which you send a valid, timely ASN. Missing ASNs don’t just trigger chargebacks; they delay Amazon’s ability to make your product available for sale. If the ASN isn’t in the system when the freight arrives, the product sits in a manual queue instead of going live on the site — and that lost availability window is real revenue Amazon can’t recover, which is why they take it seriously.

Invoice Accuracy Rate — the percentage of 810 invoices that match the original PO in price, quantity, and terms. Discrepancies don’t just cause deductions; they hold up your payment. Amazon’s payment system won’t release funds on an invoice that doesn’t reconcile, and resolving an invoice dispute through Vendor Central’s dispute workflow can take weeks.

Each of these metrics has a compliance threshold, and falling below it is automatic — Amazon’s systems apply deductions without a human reviewing whether the chargeback is fair. That’s why monitoring your Vendor Central performance dashboard isn’t optional; by the time a buyer reaches out about your metrics, the deductions have already been taken.

US and Canada: Separate Accounts

Amazon Canada (amazon.ca) operates as a separate Vendor Central account with its own EDI requirements, connection, and transaction sets. If you sell to both Amazon US and Amazon Canada — and many suppliers do — you’re maintaining two EDI relationships, two AS2 connections, and two sets of compliance thresholds. They don’t share a scorecard, and being in good standing on the US side doesn’t carry over.

This catches suppliers off guard because the brand and product listings may look unified from the consumer side. Operationally, they’re two distinct programs. If you’re expanding into Amazon Canada, plan for a full second onboarding cycle — connection setup, transaction set testing, and certification — rather than assuming your US setup transfers.

What to Watch After Go-Live

Once you’re live in Vendor Central, the single most important habit is checking your performance dashboard regularly — not weekly, but daily during your first few months. Amazon’s chargebacks are automatic and immediate, and because OPP metrics are trend-based, a few bad days can pull your rolling score below threshold before you’ve noticed. Catch a dip early and you can fix the root cause before it compounds into a buyer conversation or reduced PO volume.