How a retailer EDI onboarding actually runs
The letter usually says the same thing: from a certain date, the retailer will only accept purchase orders, order responses, advance ship notices and invoices electronically, and here is the compliance guide. The date is rarely negotiable. The work between the letter and the first accepted production document is more predictable than it looks.
The sequence
1. Read the compliance guide against your own business. The guide describes the documents, the fields, the order models the retailer runs, the labels, and the timing rules. The first job is to mark what you already have, what your ERP can produce but does not yet, and what it cannot produce at all. This is where most onboardings go wrong: skipping straight to the mapping without knowing which order model you will be trading under.
2. Write the mapping specification. For each document, a table: the retailer's field, where it comes from in your ERP, and any transformation. Pack level quantities, GLNs, dates, unit of measure codes. The specification is what you test against, what your network provider builds from, and what you will read in two years when something changes.
3. Set up the partner, the locations and the GLNs. The retailer's GLNs for its distribution centres and stores, your own for ship-from and bill-to, and the trading partner record in your network. If a GLN is not mapped, the purchase order will not be accepted, so this step comes before any test document.
4. Test with real orders. The retailer or its network sends test purchase orders. You respond with order responses, ASNs and invoices generated from your ERP, not typed by hand. The point of the test is to find out what your system actually produces. A test passed with hand-edited documents proves nothing.
5. Certification. The retailer's network reviews a set of test documents against the guide and signs off. Expect at least one round of corrections. Three to five working days of effort over the retailer's certification cycle is a fair expectation when the master data was ready beforehand; it stretches when it was not.
6. First production documents. The first live order through the whole chain, watched closely: order in, response out, goods packed and labelled, ASN before the truck, invoice after. Then a one-page runbook for whoever runs it day to day.
Who does what
The retailer owns the guide and the acceptance. The network provider owns the connection and often the translation. Your ERP partner or administrator owns changes inside the ERP. The gap in the middle, between what the retailer wants and what the ERP has, is the work. It is the specification, the master data, the test plan and the liaison with everyone else. Someone has to own that gap, and it is usually the thing nobody has budgeted for.
What has to be ready in the ERP
- GTINs at every pack level you will ship: unit, inner, carton, and pallet where the retailer requires it.
- A customer record and a ship-to GLN for every location the retailer will order for.
- Pack configurations that match the physical cartons, so the ASN hierarchy is true.
- Carton labels with SSCCs produced from the same data that builds the ASN.
- Pricing that agrees with the retailer's price file, because an invoice that disagrees with the order is a rejection.
Every one of these is master data, not EDI. That is the reason an onboarding that looks like an integration project turns out to be a data project with an integration at the end.
The date
When the retailer's date is close, start from what blocks certification: GLNs, pack data and the mapping specification. Everything else can follow. A supplier who arrives at the test with clean master data certifies quickly; one who arrives with a perfect mapping and an untidy product master does not.