How integrations connect brands and retailers: EDI, APIs and files
Orders, product data, stock and invoices flow between brands and retailers through three main routes. A practical guide to choosing and running each one.
KEY TAKEAWAYS Summary by the editors
- Brand and retailer systems exchange data through three main routes: EDI messages, APIs and structured file exchange.
- EDI is the established standard for orders, dispatch advice and invoices with larger retailers, while APIs suit real-time needs such as stock and order status.
- File exchange remains common for product data and smaller partners, and is acceptable when it is automated, scheduled and validated.
- The integration method matters less than agreed data standards, especially consistent product identifiers such as GTINs.
- Every integration needs monitoring and a named owner, because silent failures cause missed orders and wrong stock.
A department store places a replenishment order on Monday morning. By the afternoon the brand needs to confirm it, by Wednesday the goods ship with a dispatch notice, and the invoice follows. If any of those steps relies on someone retyping data from an email, errors and delays are almost guaranteed. Integrations exist to make these exchanges reliable, and in fashion wholesale they come in three main forms.
What data do brands and retailers exchange?
Before choosing a method, it helps to list what actually needs to move. In a typical wholesale relationship the flows include:
- Product data: styles, colourways, sizes, identifiers, prices, compositions and images, so the retailer can set up articles.
- Orders: pre-orders, re-orders and replenishment orders, plus changes and cancellations.
- Order responses: confirmations, partial confirmations and rejections.
- Dispatch information: advance shipping notices listing what is in each carton.
- Invoices and credit notes.
- Stock and sales data: brand availability for re-orders, and retailer sell-through and stock for replenishment programmes.
What are the three main integration methods?
| Method | How it works | Typical use | Main trade-off |
|---|---|---|---|
| EDI | Standardised electronic messages exchanged between business systems, often through a service provider | Orders, order responses, dispatch notices and invoices with larger retailers | Robust and widely accepted, but slower to set up and less flexible |
| API | Systems request or send data directly in real time through defined interfaces | Stock availability, order status, product data for platforms and portals | Fast and flexible, but each API is specific and needs development |
| File exchange | Structured files such as CSV or XML transferred on a schedule, often via secure FTP | Product catalogues, price lists, stock files, smaller partners | Simple and cheap, but batch-based and prone to format drift |
These methods are not mutually exclusive within one relationship either. A brand might receive orders by EDI, send product data as a file, and expose stock through an API to the same retailer. What matters is that each flow has a defined method, schedule and owner.
Most brands run all three. A large retailer may insist on EDI for orders and invoices, a marketplace may offer only an API, and a smaller boutique group may accept a weekly product file. The goal is not uniformity but control.
How do you choose the right method for each partner?
- Start with the partner's requirements. Larger retailers usually publish integration guidelines and mandatory message types. Those are not negotiable.
- Match speed to the business need. Stock for re-orders benefits from near real-time updates. Product catalogues can usually move in daily or seasonal batches.
- Consider volume. A partner placing a handful of orders per season may not justify a full EDI setup. A partner sending daily replenishment orders almost certainly does.
- Reuse what exists. If the ERP or an integration platform already supports a standard, extending it is usually cheaper than building something new.
- Plan for change. Partner formats evolve. Prefer approaches where mappings can be updated without rewriting systems.
Why do integrations fail, and how do you prevent it?
Most integration problems are not technical outages. They are data problems that pass silently: an order for a size that does not exist in the brand's system, a price that differs between the retailer's catalogue and the brand's price list, or a dispatch notice that does not match the physical cartons. Common preventive measures include:
- Validating incoming orders automatically and flagging exceptions to a named person rather than a shared mailbox.
- Sending product data to retailers from a single approved source, so identifiers and prices match.
- Monitoring message flows with alerts when expected files or messages do not arrive.
- Testing every new partner with real sample orders before go-live, covering size runs, prepacks and cancellations.
- Keeping documentation of each mapping, so knowledge does not sit with one developer.
Who should own integrations inside a fashion brand?
Integrations sit between departments, which is why they are often orphaned. IT or an external partner builds them, sales owns the retailer relationship, logistics depends on the dispatch notices and finance on the invoices. When something breaks, each assumes another team is responsible.
A clear model assigns technical ownership to IT or an integration partner and business ownership per flow: sales operations for orders, logistics for dispatch, finance for invoices and the product data team for catalogues. Regular reviews with key retailers, especially before each selling and delivery period, catch format changes before they disrupt the season. Treated this way, integrations stop being a hidden source of friction and become part of the service a brand offers its wholesale partners.
Frequently asked questions
Will APIs replace EDI in fashion?
APIs are growing, especially for real-time data such as stock and order status, but EDI remains deeply embedded in retailer processes for orders, dispatch and invoicing. Most brands should expect to run both for the foreseeable future.
Is file exchange outdated?
Not necessarily. Scheduled, validated file exchange works well for product catalogues, price lists and smaller partners. The risks come from manual handling and unannounced format changes, not from files as such.
What is an integration platform?
An integration platform, sometimes called middleware or iPaaS, sits between systems and handles mapping, routing and monitoring of data flows. It lets brands manage many partner connections in one place rather than building each one into the ERP.
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