X12 transaction guide · Transportation

EDI 423 Rail Industrial Switch List

The X12 document used to produce switch lists and equipment notifications for switching at customer sidings.

Sent by
Shipper or rail carrier
Received by
Rail carrier or shipper
Standard
ANSI ASC X12

What is an EDI 423?

The EDI 423 Rail Industrial Switch List is the ANSI X12 transaction set intended solely for producing switch lists and equipment notifications, and for providing switching information agreed between customers and carriers. It is not used to record release times or order empty equipment.

At an industrial plant served by rail, cars must be placed at the right loading spots and pulled when ready. The switch list tells the local crew which cars to pull, which to place and where, so the work is done in one visit.

How the EDI 423 worksDiagram of the EDI 423 Rail Industrial Switch List. Shipper or rail carrier sends it to rail carrier or shipper. It usually starts the exchange. It is usually followed by 997. Inside the ISA, GS and ST envelopes, X12 release 008010 requires, in the heading: BGN (Beginning Segment) and the required N1 loop with N1 (Party Identification). 1 optional loops are listed by their first segment.How the EDI 423 worksRail Industrial Switch List: who sends it, where it fits and what the standard marks required1 WHERE IT FITSUSUALLY FOLLOWSStarts the exchangeEDI 423SENDERShipper or rail carrierRECEIVERRail carrier or shipper997 or 999 acknowledgment back, if the partners agreeUSUALLY FOLLOWED BY997FunctionalAcknowledgment2 WHAT X12 RELEASE 008010 REQUIRESInterchange: sender and receiver IDsISA … IEAFunctional group, ID code RLGS … GETransaction set 423ST … SEHEADINGBGNBeginning SegmentRequired loop N1 · repeats up to 5N1Party Identification+ 1 optional loop, starting with:LXBlue box: required loop. Optional loops are listed by the segment that starts them; when a loop is used, that first segment is required. Optional segmentsoutside loops are not drawn.Structure: required segments and loops in the X12 008010 listing for the 423. Your trading partner's implementation guide adds its own requirements.
How the EDI 423 worksDiagram of the EDI 423 Rail Industrial Switch List. Shipper or rail carrier sends it to rail carrier or shipper. It usually starts the exchange. It is usually followed by 997. Inside the ISA, GS and ST envelopes, X12 release 008010 requires, in the heading: BGN (Beginning Segment) and the required N1 loop with N1 (Party Identification). 1 optional loops are listed by their first segment.How the EDI 423 worksRail Industrial Switch List: who sends it,where it fits and what the standard marksrequired1 WHERE IT FITSUSUALLY FOLLOWSStarts the exchangeEDI 423SENDERShipper or railcarrierRECEIVERRail carrier orshipper997 or 999 acknowledgment back, if the partnersagreeUSUALLY FOLLOWED BY997Functional Acknowledgment2 WHAT X12 RELEASE 008010 REQUIRESInterchange: sender and receiver IDs (ISA… IEA)Functional group, ID code RL (GS … GE)Transaction set 423 (ST … SE)HEADINGBGNBeginning SegmentRequired loop N1 · repeats up to 5N1Party Identification+ 1 optional loop, starting with:LXBlue box: required loop. Optional loops are listedby the segment that starts them; when a loop isused, that first segment is required. Optionalsegments outside loops are not drawn.Structure: required segments and loops in the X12008010 listing for the 423. Your trading partner'simplementation guide adds its own requirements.

How to read this diagram: the top row shows who sends the 423, to whom, and which documents usually come before and after it. The lower part shows what X12 release 008010 itself requires: the envelopes around the 423 and the segments and loops the standard marks as required, area by area. Optional loops are listed by the segment that starts them rather than drawn in full. This is the standard's minimum, not a trading partner's requirement: each partner's implementation guide usually makes some optional loops mandatory, restricts the codes and may use a different release.

Expand diagram Download SVG

When it is used

  • Telling the local crew which cars to pull and place
  • Notifying customers of cars placed
  • Sharing agreed switching instructions

Where it fits in the document flow

This document 423 Rail Industrial Switch List
Usually followed by 997 Functional Acknowledgment

Structure

Mandatory segments in the 423 (X12 release 008010)

The segments X12 release 008010 marks as mandatory at their level, in order. Segments inside optional loops are needed only when the loop is used. This is the standard's requirement, not your trading partner's: each partner's implementation guide names the release it uses, adds the optional segments it requires and restricts the values. The requirement status comes from one published X12 reference listing and has not been checked against a second source.

  • ST
  • BGN
  • N1
  • LX
  • N7
  • LH1
  • SE

Practical example

The 423 in practice

A grain elevator has eight loaded cars ready and needs ten empties placed. Before the local train's daily visit, the elevator sends the railroad a 423 switch list naming the loaded cars to pull and the track positions for the empties. The crew follows the list, and the railroad confirms the placement.

Implementation

Implementation considerations for the 423

  • Send the list before the local crew's visit.
  • Identify track positions as agreed with the railroad.
  • Use the 423 for switching only, not for car orders.
  • Confirm completed work against the list.

Need help with the EDI 423?

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