You signed the contract with a discount chain. Two weeks in comes the email: "Please launch EDI within 30 days." That's when the fun starts, because the same three letters hide three completely different solutions at three completely different price points.
EDI (Electronic Data Interchange) isn't a single standard. It's an agreement that specific commercial documents will be exchanged with the chain electronically, in a specific format, with specific fields and GLN identifiers. Every chain has its own guidelines, its own list of mandatory messages and its own threshold for "from how many pallets you have to do EDI". Biedronka, Lidl, Kaufland, Carrefour, Auchan, Selgros — each is different. So the first decision in an EDI project isn't picking a vendor, it's picking a technical path.
What "the chain requires EDI" actually means
A small supplier usually hears three messages. ORDERS is an order from the chain to you. DESADV (also called ASN) is the dispatch advice — exactly what is leaving the warehouse for a specific delivery. INVOIC is the invoice in EDI form — and note, this is not the same as a KSeF e-invoice (Poland's national e-invoicing system). Some chains add RECADV (proof of receipt — how much the store actually took in) and ORDRSP (your confirmation of the order).
These are not formalities. The chain measures SLAs in hours: the order arrives, you have X hours to send ORDRSP, Y to send DESADV before the truck leaves, Z for INVOIC after delivery. Miss the window and you get penalty clauses and a hit on your supplier rating. In our experience the "30-day deadline to launch EDI" usually only covers the portal path. A real, integrated launch with your ERP takes 6 to 16 weeks.
Three technical paths
From a 15-50-person company's perspective, you have three realistic options.
The first — cheapest, worst in the long run — is the EDI operator's web portal. You log in through a browser, manually re-type order lines into a form, click "send DESADV". It works, costs 200-500 PLN per month and usually adds a one-off 1 500-3 000 PLN setup fee. It scales badly: at 20 orders per week that's several hours of manual work per day, and you still have to retype the data into your ERP afterwards.
The second — the right answer for most SMEs — is EDI operator plus ERP integration. The operator (Comarch EDI, Edison, Infinite IT, EDInet and a few others) receives the chain's message, translates it from EDIFACT into whatever your ERP can swallow and writes it into the database. Invoices go from ERP to operator to chain on the way back, translated to EDIFACT en route. You only see your normal Comarch Optima, enova365 or Subiekt GT screens.
The third — your own AS2/SFTP implementation with EDIFACT parsing. Only sane if you have an in-house IT team and specific requirements no operator covers. For an 18-person company it's the classic "but it was cheaper" story. Six months in nobody can maintain it — the first EDIFACT specialist who leaves takes the knowledge with them.
A real example
At one of our customers — an 18-person producer of pickled vegetables from the Wielkopolska region, ERP Comarch Optima, deliveries to two discount chains — the pre-integration setup looked like this: every morning, two people in the back office re-typed orders from the chain's portal into Optima. About 90 minutes per person. In the evening the same route in reverse — invoices from Optima were manually keyed into the chain's portal, "because otherwise the chain's system won't accept them". Roughly 40 hours of work per month eaten by retyping.
Plus the mistakes. Someone typed 24 pieces instead of 240, someone forgot a promotional price, someone sent DESADV after the truck had already left. Each error meant a complaint, sometimes a chargeback note. Across a year, a few thousand zloty of "chaos penalties", plus a growing list of remarks from the buyer.
We rolled out an EDI operator (Comarch EDI in this case, since they were on Optima already) and a two-way integration. Three months end to end — six of those weeks were spent agreeing GTIN codes, logistic units and party-code mappings. After go-live both back-office staff got an hour back per day — about 40 hours per month flowing back into actual customer service. Quantity complaints dropped roughly 80%. Cost: one-off 11 000 PLN for the integration plus 650 PLN per month for the operator and two EDI channels. Payback measured in "chaos penalties" alone: seven months. In recovered staff time, faster.
Costs the first quote won't show you
EDI operator quotes show two lines: a setup fee and a monthly subscription. The real project budget has three more.
ERP integration. It's a separate IT project on a separate invoice, often from a different vendor than the EDI operator itself. Comarch Optima typically uses the Comarch EDI module; enova365 has a dedicated connector; Subiekt GT and older systems usually need middleware. Cost: anywhere from 5 000 to 25 000 PLN depending on the ERP and number of message types.
Master-data cleanup. Every product you ship to the chain needs a valid GTIN, correct logistic units (units per box, boxes per pallet, pallets per truck) and an up-to-date item code on the chain's side. In most companies the first week of the project is discovering that half the catalogue is missing this data or has it wrong. Without cleanup EDI won't start — the chain simply rejects malformed messages.
The first chain pulls the second in — but asymmetrically. Adding a second chain on the same operator is often only a 1 500-3 000 PLN top-up. A third one, similar. Good news: once you have the infrastructure, more buyers are cheap. Bad news: every chain has its own format quirks and optional-field requirements. "Cheap" doesn't mean "two clicks".
What to watch when picking an operator
EDI operator quotes look surprisingly similar. The devil sits in five questions the first sales meeting won't cover.
- Does the operator support the exact chains you're entering? Most cover the top 10, but if you have an unusual regional buyer or a HoReCa distributor, verify them by name.
- What does "integration with Comarch Optima/enova365" actually mean? Does the operator write messages directly to the ERP database, or send XML files that someone has to import by hand? Two completely different operational worlds.
- Who fixes a rejected invoice at 22:00 on a Friday? Under what procedure, what response time, at what cost. This question reveals whether the offer is real or just a price sheet.
- What if you want to change operators in a year? Will historical messages stay with you, or in the operator's cloud? EDI operator migration without preserved history is painful and in some industries blocks tax audits.
- How do you pay — per message, per channel, flat fee? During seasonal spikes (Christmas, Black Friday on food) "per-message" models can produce an invoice three times the average.
When to start the conversation
The email from the chain says "30 days". Realistically, an EDI rollout with ERP integration takes 6-10 weeks with clean master data, 12-16 weeks with dirty master data. If the chain has already written to you, today is a good day to start talking to an operator and to whoever owns your ERP in parallel — not one after the other.
If you already have EDI "for years" in the portal version and want to move to full integration, you can typically do it without downtime, running manual handling as a fallback for the first month. You don't have to choose between "everything from scratch" and "keep retyping forever".
If you don't know which path to take or which operator to talk to, instead of reading brochures, spend half an hour with someone who breaks these projects down for a living. The first call is free.
EDI is not an IT project. It's an operations project where IT is one of four threads, alongside master data, logistics and finance.