TRADACOMS

The first nationwide-scale EDI standard, created in 1982 by the UK Article Number Association. In 2026 it still carries the majority of UK grocery EDI traffic across legacy retail estates.

What is TRADACOMS?

TRADACOMS — TRAnsmission of DAta COMmercially Standard — is the first production EDI standard ever deployed at the scale of a whole country. It was introduced in 1982 by the Article Number Association (ANA), today GS1 UK, to end the proliferation of proprietary formats then in use between Tesco, Sainsbury's, Boots and their suppliers.

The standard was built on the UN/GTDI syntax (Guidelines for Trade Data Interchange) — the UN syntax later generalised worldwide as EDIFACT in 1987. TRADACOMS is therefore the direct ancestor of EDIFACT: same principle of three-letter segment tags, same textual separators, same split between transmission envelope, message header, body and trailers.

Anatomy of a TRADACOMS file

A TRADACOMS file packs one or more business messages into a transmission envelope delimited by STX (Start of Transmission) and END. Inside, each message is wrapped by a MHD (Message Header) and a MTR (Message TRailer). A very condensed ORDERS file:

STX=ANAA:1+5012345000007:TESCO+5000123000004:NORTHERN+260514:000001+ORD-19872'
MHD=1+ORDHDR:9'
TYP=0430:ORDERS HEADER FILE'
SDT=5012345000007:TESCO STORES PLC'
CDT=5000123000004:NORTHERN BRANDS LTD'
FIL=1+1+260514'
MTR=6'
MHD=2+ORDERS:9'
CLO=5012345000014:STORE-LONDON-SW1:1 HIGH STREET LONDON'
ORD=PO-2026-009881:260514'
DIN=260518:0001+S'
OLD=1+5000123010001::C+CRUNCHY BISCUITS 200G+24:EA+1.20+28.80'
OLD=2+5000123010018::C+OAT COOKIES 250G+12:EA+1.80+21.60'
OTR=2'
MTR=8'
MHD=3+ORDTLR:9'
OFT=2'
MTR=3'
END=3'

Quick reading guide:

• STX — Start of Transmission, identifies sender, receiver, date and an interchange number.
• MHD — Message HeaDer, opens a message and names it (here ORDHDR, ORDERS, ORDTLR) plus the version number.
• Business segments — for instance CLO (Customer Location), ORD (Order Reference), DIN (Delivery INstructions), OLD (Order Line Details).
• MTR — Message TRailer, gives the total number of segments in the message.
• END — end of transmission, with the total number of messages.

Key segments

TRADACOMS defines around fifty segments covering the full retail flow. The 90% you will encounter in real files:

Common messages

A TRADACOMS file usually contains a header / body / trailer trio. The standard publishes about twenty-five message types, but the bulk of the traffic is concentrated on the following:

TRADACOMS vs EDIFACT

Both standards share the same common ancestor (UN/GTDI) but differ on several practical points:

Adoption in 2026

Although TRADACOMS development was officially frozen in 1995 in favour of EANCOM (the retail-focused EDIFACT subset stewarded by GS1 Global), the majority of UK retail EDI traffic still flows over TRADACOMS. The inertia comes from:

• accounting depreciation of legacy EDI platforms (a major UK retailer has typically invested twenty years into its TRADACOMS hub);
• the presence of specialised UK VAN operators (GXS / OpenText, IBM Sterling) who run large TRADACOMS↔EDIFACT mapping fleets and bill the traffic without pushing migration;
• the stability of trading partners: the UK grocery chains (Tesco, Sainsbury's, Asda, Morrisons, Waitrose, Boots) and their largest historical suppliers (Unilever, Procter & Gamble, Nestlé, Reckitt) have been connected for decades;
• the near-absence of new regulation forcing a migration (unlike the continent where e-invoicing pushes PEPPOL).

In UK pharmacy and drugstore, TRADACOMS is still in use at Boots, Lloyds Pharmacy and Superdrug. In the book trade, BIC (Book Industry Communication) keeps publishing proprietary extensions to TRADACOMS for publisher / bookseller flows, where the format remains the de-facto industry standard.

Future: EANCOM and beyond

The long-term migration target is EANCOM — the EDIFACT profile stewarded by GS1 Global for the retail industry. EANCOM reuses EDIFACT messages (ORDERS, DESADV, INVOIC, RECADV…) with retail-specific usage rules: GTIN product codes, GLN party codes, standard commercial terms.

More broadly, new entrants in the UK (Ocado, Lidl GB, digital-native retailers) plug in directly through APIs or PEPPOL without ever transiting through TRADACOMS. The transition will happen by attrition: as legacy platforms get rebuilt, TRADACOMS will fade out functionally. Its current longevity nonetheless illustrates one EDI rule of thumb: a working, depreciated standard does not die — it survives until regulation forces the change.

Further reading

• GS1 UK — official maintainer of the TRADACOMS and EANCOM specifications.
• Wikipedia — TRADACOMS — standard history, comparison with EDIFACT, message list.
• EDIFACT on ediverse — official successor and the long-term replacement standard.
• UBL / PEPPOL on ediverse — likely landing spot for new UK entrants, particularly for e-invoicing.