VAN vs. AS2: Choosing the Right EDI Connection Method

When you set up EDI with a new trading partner, you have to choose how your documents physically travel between your system and theirs. The two options are a VAN (Value-Added Network) — an intermediary that receives your documents and routes them to the correct trading partner, like an EDI post office — or AS2 (Applicability Statement 2), a direct, encrypted, point-to-point connection between your system and the retailer’s with no intermediary. The choice isn’t about which is "better" in the abstract. It’s a decision with real tradeoffs around cost structure, who maintains the connection, and — most importantly — which retailers you need to reach, because some retailers mandate one method and won’t accept the other.

The First Question: What Do Your Retailers Require?

Before evaluating tradeoffs, check what your trading partners actually accept, because this may decide the question for you. Walmart, Amazon, and Target mandate AS2 — they will not accept VAN connections for their EDI traffic. If you’re onboarding with any of these retailers, you need AS2, and the rest of the decision framework is irrelevant for those connections. Other retailers — Costco, many grocery chains, many smaller regional retailers — accept VAN connections. Some suppliers end up using both: AS2 for the major retailers that require it, and VAN for smaller trading partners that don’t mandate AS2. So the first step in the decision is mapping out your retailer list and identifying which ones dictate the connection method.

The Cost Structure Tradeoff

This is where the decision gets real for growing suppliers, and the tradeoff depends on your transaction volume:

VAN pricing is typically per-transaction — you pay a fee for each document the VAN routes on your behalf. At low to moderate volume, this is manageable. As your order volume grows — more retailers, more POs, more ASNs, more invoices — the per-transaction fees scale with your volume. A supplier doing 500 transactions per month pays five times what a supplier doing 100 transactions pays, even though the VAN’s infrastructure cost to serve them isn’t proportionally different. At high volume, per-transaction VAN pricing becomes a significant line item that grows with your business.

AS2 pricing is typically flat — you’re maintaining a direct connection, not paying per document routed. There’s no per-transaction fee because there’s no intermediary processing each document. The cost is in the infrastructure: an AS2 server (or a managed provider maintaining one), digital certificates, and the setup for each trading partner connection. Once the connection is established, your marginal cost per transaction is effectively zero — you can send 1,000 documents or 10,000 through the same AS2 connection for the same infrastructure cost.

The decision framework: if you’re a low-volume supplier with a few trading partners and moderate transaction counts, VAN’s per-transaction model may be cheaper than the infrastructure cost of setting up and maintaining AS2 connections. If you’re a high-volume supplier with significant transaction counts, AS2’s flat cost structure will almost certainly be cheaper — and the per-transaction VAN fees will have become a growing expense that scales with your success.

Who Maintains the Connection

The maintenance burden differs significantly between the two, and this matters if you don’t have a dedicated EDI team:

VAN maintenance is minimal. The VAN handles the intermediary infrastructure — you connect to the VAN once, and the VAN routes to all your trading partners who are also on that VAN (which is most of them). You don’t manage individual connections, certificates, or endpoints per trading partner. The VAN handles queuing, retry, and delivery confirmation. This simplicity is the VAN’s core value — one connection relationship, and the VAN handles the complexity of routing to thousands of potential partners.

AS2 maintenance is per-connection. Each retailer you connect to via AS2 requires a separate connection configuration: exchanging digital certificates, configuring endpoint URLs, verifying bidirectional transmission, and managing certificate renewals (typically annually). If a certificate expires, that connection goes down — and ASNs stop transmitting to that retailer until it’s renewed. For a supplier with AS2 connections to five major retailers, that’s five connections to maintain, five sets of certificates to track, and five potential points of failure. This is manageable with a managed EDI provider who handles certificate management automatically; it’s a real operational burden if you’re maintaining AS2 connections yourself without dedicated EDI staff.

Transmission Speed

AS2 transmits in seconds — direct, point-to-point, no intermediary processing. VAN transmissions typically take minutes — your document goes to the VAN, the VAN processes and routes it, and it arrives at the trading partner’s mailbox. For most EDI transactions, the difference between seconds and minutes doesn’t matter — an 810 invoice arriving in two minutes versus two seconds is operationally irrelevant. Where it matters is ASN timing for retailers with tight windows. Walmart’s 30-minute ASN window is tight enough that a VAN’s processing delay eats into your margin — and since Walmart mandates AS2 anyway, the point is moot for that retailer. For retailers with looser ASN windows that accept VAN, the transmission delay is rarely the deciding factor.

Making the Decision

The decision framework, in order:

1. Which retailers mandate AS2? Those connections require AS2 regardless of your preference.
2. For retailers that accept either — what’s your transaction volume? High volume favors AS2’s flat cost structure; low volume favors VAN’s per-transaction model.
3. Do you have EDI infrastructure expertise in-house? If not, either choice requires a managed provider — and a provider can maintain either or both connection types on your behalf.
4. How many trading partners do you have? Few partners with high volume each favors AS2. Many partners with low volume each favors VAN’s one-connection-serves-all simplicity.

Most established suppliers end up with both: AS2 for major retailers who require it (and where the volume justifies the infrastructure), and VAN for smaller trading partners where the per-transaction model is cheaper and the connection simplicity is worth it. Spring Systems manages both connection types — the decision is about which method serves each trading partner relationship, not about committing to one approach for everything.