TRADACOMS

The UK retail EDI standard that pioneered electronic trading in British commerce

Overview

TRADACOMS (Trading Data Communications Standard) is an EDI standard developed specifically for the UK retail sector. Created by the Article Number Association (ANA), now known as GS1 UK, TRADACOMS was one of the earliest EDI standards to achieve widespread commercial adoption. It defines message formats for common retail trading documents such as purchase orders, invoices, delivery notifications, and credit notes.

Although UN/EDIFACT was intended to replace TRADACOMS as the international standard, TRADACOMS has proven remarkably persistent in the UK market. Thousands of UK trading relationships still rely on TRADACOMS, and it remains the most commonly used EDI standard among British retailers and their supply chains. Its longevity is a testament to the difficulty of migrating established EDI infrastructures, even when technically superior alternatives exist.

History

TRADACOMS was first published in 1982 by the ANA as a set of message standards tailored to UK retail trading practices. It was developed in response to the growing need for electronic communication between retailers and their suppliers. The standard drew on early work in EDI that had been pioneered in the United States but adapted the concepts for British commercial conventions, including UK-specific addressing, VAT handling, and order processing workflows.

By the mid-1980s, major UK retailers such as Tesco, Sainsbury's, and Marks & Spencer had adopted TRADACOMS, creating strong network effects that drove adoption among their suppliers. The standard was updated periodically through the 1980s and 1990s, but development effectively ceased in 1995 when GS1 UK announced that EDIFACT (specifically the EANCOM subset) would be the path forward.

Despite this announcement, TRADACOMS has continued in active use for over three decades after its "replacement" was declared. The cost and risk of migrating established EDI connections has kept TRADACOMS firmly embedded in UK retail supply chains.

Structure and Format

TRADACOMS uses a fixed-format, segment-based structure that is simpler than both X12 and EDIFACT. Messages are composed of segments, each identified by a three-character tag, with data elements separated by specific delimiters.

Delimiters

  • Segment terminator: apostrophe ('), similar to EDIFACT
  • Data element separator: equals sign (=)
  • Sub-element separator: colon (:)

Envelope Structure

  • STX - Start of Transmission (sender, recipient, date/time, application reference)
  • BAT - Batch Header (optional, groups related messages)
  • MHD - Message Header (message type, reference number)
  • Message body segments - Business data specific to the message type
  • MTR - Message Trailer
  • EOB - End of Batch (if BAT used)
  • END - End of Transmission

Example

A simplified TRADACOMS ORDHDR (Order Header) message: 

STX=ANA:1+5012345678900:RETAILER+5098765432100:SUPPLIER+230615:1200+ORDERS004'
MHD=1+ORDHDR:9'
TYP=0430+NEW ORDERS'
SDT=5012345678900:RETAILER'
CDT=5098765432100:SUPPLIER+SUPPLIER LTD'
FIL=1+1+230615'
MTR=6'
MHD=2+ORDERS:9'
CLO=5012345678900::STORE001+STORE NAME'
ORD=PO-12345:230615+230617::+N'
DIN=230618+230620'
OLD=1+5000127000010:9+:50+:EACH+:+250'
MTR=7'
MHD=3+ORDTLR:9'
OTL=1'
MTR=3'
END=3'

Key Message Types

TRADACOMS defines a focused set of message types for retail trading:

  • ORDHDR / ORDERS / ORDTLR - Purchase Order (header, detail lines, trailer)
  • INVFIL / INVOIC / IVCTLR - Invoice
  • DLCHDR / DELIVR / DLCTLR - Delivery Notification
  • CREHDR / CREDIT / CRDTLR - Credit Note
  • SNPSTS - Stock Snapshot
  • PRIINF - Price Information
  • ACKHDR / ACKNOW / ACKTLR - Order Acknowledgment
  • AVLHDR / AVAILA / AVLTLR - Availability Report
  • UCNHDR / UTLHDR - Utility Bill Header

Use Cases

  • UK grocery retail: The primary domain for TRADACOMS, handling order-to-invoice cycles between supermarket chains and food/beverage suppliers
  • General merchandise: Department stores and high-street retailers use TRADACOMS for non-food product ordering and invoicing
  • Wholesale distribution: Wholesalers and cash-and-carry operators exchange TRADACOMS documents with both suppliers and trade customers
  • DIY and home improvement: UK home improvement retailers adopted TRADACOMS for supply chain management

Advantages

  • Simplicity: TRADACOMS is simpler and more straightforward than EDIFACT or X12, making it easier to implement and debug
  • UK retail focus: Designed specifically for UK retail practices, so it fits the business processes naturally
  • Established base: Thousands of active trading relationships ensure ongoing support from EDI service providers and VAN operators
  • Low migration cost: Existing TRADACOMS implementations work reliably, reducing the business case for migration

Related Standards

TRADACOMS is most closely related to UN/EDIFACT and specifically the EANCOM subset, which is its intended successor for UK retail EDI. New UK trading relationships are more likely to be established using EANCOM or XML-based standards, while legacy TRADACOMS connections are maintained. In the broader European context, EDIFACT is the dominant standard, and TRADACOMS is unique to the UK market. For modern alternatives, many UK retailers are exploring API-based EDI approaches alongside their traditional TRADACOMS infrastructure.