If this is your first time exchanging X12 documents, you may be wondering which communication identifiers to supply your trading partner. Identifiers can be requested for ISA (interchange envelope) and GS segments (functional group) and can differ between production and test transactions. So, you can have between 1 and 4 identifiers depending on your trading partner's requirements or your EDI needs.

If you can avoid it, for simplicity, we recommend using the same identifiers for both ISA and GS segments. For test and production messages however, it can either simplify or complicate your setup to use the same identifiers both ways. For example, if you intend on handling test and production messages in separate channels, choosing different identifiers can be a good way to route messages one way or another.

An X12 communication ID involves two parts:

• A 2 character code indicating what your identifier represents. X12 refers to this code as the qualifier.
• A maximum 15 character free text (but stick to letters and numbers) which is the ID itself. 

Although X12 authorizes all sorts of identifiers. These are the most common:

• ZZ - Mutually defined: This one is the simplest. You will typically use your company name. For most protocols, all you need is for this identifier to be unique among your trading partner's partners. However, if you decide to register on a VAN (value added network) your identifier will need to be unique across more or less the north American market. And depending on your company name, this may not be the best identifier choice. Also, note that you should be careful about any special characters you would use in your identifier since they could end up being used as separators in your dealings with trading partners and may end up involuntarily breaking the structure of your message.
• 01 - DUNS: Most common especially among retailers and naturally unique.
• 12 - Phone: This one is naturally unique as well although not as telling from a human point of view.

For example, if Babelway were to opt for a mutually defined identifier, our ISA might look like this (note the "ZZ*BABELWAY"):

ISA*59* *59* *12*9419442114 *ZZ*BABELWAY *171594*1924*|*59423*159595912*2*P*>~

This is the list of codes for X12 version 4010. Note that this list can differ slightly depending on the X12 standard. It's possible earlier versions don't support some of these codes.

01 - Duns (Dun and Bradstreet) 

02 - SCAC (Standard Carrier Alpha Code) 

03 - FMC (Federal Maritime Commission) 

04 - IATA (International Air Transport Association) 

08 - UCC EDI Communications ID (Comm ID) 

09 - X.121 (CCITT) 

10 - Department of Defense (DoD) Activity Address Code 

11 - DEA (Drug Enforcement Administration) 

12 - Phone (Telephone Companies) 

13 - UCS Code (The UCS Code is a Code Used for UCS Transmissions; it includes the Area Code and Telephone Number of a Modem; it Does Not Include Punctuation, Blanks or Access Code) 

14 - Duns Plus Suffix 

15 - Petroleum Accountants Society of Canada Company Code 

16 - Duns Number With 4-Character Suffix 

17 - American Bankers Association (ABA) Transit Routing Number (Including Check Digit, 9 Digit) 

18 - Association of American Railroads (AAR) Standard Distribution Code 

19 - EDI Council of Australia (EDICA) Communications ID Number (COMM ID) 

20 - Health Industry Number (HIN) 

21 - Integrated Postsecondary Education Data System, or (IPEDS) 

22 - Federal Interagency Commission on Education, or FICE 

23 - National Center for Education Statistics Common Core of Data 12-Digit Number for Pre- K-Grade 12 Institutes, or NCES 

24 - The College Board's Admission Testing Program 4- Digit Code of Postsecondary   Institutes, or ATP 

25 - American College Testing Program 4-Digit Code of Postsecondary Institutions, or   ACT 

26 - Statistics of Canada List of Postsecondary Institutions 

27 - Carrier Identification Number as assigned by Health Care Financing Administration   (HCFA) 

28 - Fiscal Intermediary Identification Number as assigned by Health Care Financing Administration (HCFA) 

29 - Medicare Provider and Supplier Identification Number as assigned by Health Care Financing Administration (HCFA) 

30 - U.S. Federal Tax Identification Number 

31 Jurisdiction Identification Number Plus 4 as assigned by the International Association of Industrial Accident Boards and Commissions (IAIABC) 

32 - U.S. Federal Employer Identification Number (FEIN) 33 National Association of Insurance Commissioners Company Code (NAIC) 

34 - Medicaid Provider and Supplier Identification Number as assigned by individual State Medicaid Agencies in conjunction with Health Care Financing Administration (HCFA) 

35 - Statistics Canada Canadian College Student Information System Institution Codes

36 - Statistics Canada University Student Information System Institution Codes

37 - Society of Property Information Compilers and Analysts

AM - Association Mexicana del Codigo de Producto (AMECOP) Communication ID

NR - National Retail Merchants Association (NRMA) - Assigned

SN - Standard Address Number

ZZ - Mutually Defined