What is ANSI X 12? All You Need to Know About Standards, Types, and Structure

A3Logics 08 Jun 2023


ANSI X12 is a set of Electronic Data Interchange (EDI) standards that allows businesses to exchange electronic documents and data in a uniform format. These standards form the basis for automated data transfer between organizations and their trading partners. Though initially developed for financial transactions, ANSI X12 standards now cover a wide range of common business documents including purchase orders, invoices, payments, shipping notices, human resource forms, and healthcare claims. The standards define the structure, data elements, codes, and syntax for each type of document so they can be interpreted consistently across different systems.

Implementing ANSI X12 standards enables businesses to automate manual processes, reduce errors and improve the speed and efficiency of exchanging information with partners. Large companies often require their suppliers and customers to comply with ANSI X12 to streamline their supply chains.


What is ANSI X12?


ANSI X12 is a standard developed by the American National Standards Institute to manage the electronic exchange of business documents between organizations. These electronic documents include purchase orders, invoices, shipping notices, and many other types of routine business forms. The ANSI X12 standard defines data elements, documents, codes, and rules for formatting and transmitting files between businesses. Further, it helps business’s structure and sends business transaction information in a uniform way that other companies can receive and decode the data. 


As a result, this allows companies to send and receive electronic documents related to purchasing, shipping, payments, and other operational activities. Implementing the ANSI X12 standard enables businesses to exchange files efficiently in an electronic format instead of printing and mailing physical paper forms.


What are the different ANSI X12 standards?


Many ANSI X12 standards define specific types of business documents. The most common ANSI X12 standards specify formats for purchase orders, invoices, shipping notices, and payment instructions. Specific ANSI X12 EDI services standards include:

  • X12 850 – Purchase order standard
  • X12 810 – Invoice standard
  • X12 856 – Shipping notice standard
  • X12 820 – Payment order and remittance advice standard
  • X12 855 – Purchase order acknowledgment
  • X12 862 – Delivery Just-in-Time


These different ANSI X12 standards define specific data elements and codes for particular kinds of business information. They ensure the electronic files for purchase orders, invoices, claims, and other documents have a uniform structure so companies can easily receive, read and process the information across business transactions. The different ANSI X12 standards allow organizations to automate business processes involving exchanging common types of business documents with other businesses and partners.


Guidelines for ANSI X12 standard


There are some key guidelines to follow when implementing ANSI X12 standards for exchanging electronic business documents.

First, businesses need to agree on which ANSI X12 standards they will use for each type of document like purchase orders or invoices. Also, they must specify file naming conventions, transmission methods, and security protocols. It is important to test files between trading partners before going live to ensure data is mapped correctly and all required elements are included. 


Regular file audits should be done to identify any issues or errors. Businesses should have procedures in place for handling rejections, re-transmissions, and other exceptions. Training employees on the ANSI X12 standards used and change management processes help ensure a smooth transition. Finally, documentation detailing data elements, codes, file layouts, and business rules is essential for referencing and onboarding new suppliers or customers. Following these guidelines helps businesses realize the full benefits of ANSI X12 standards for improving productivity, accuracy, and costs.


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Structure of ANSI X12 standards


The ANSI X12 standards define the structure of electronic business documents to ensure consistency and compatibility.

There are 3 main parts to the structure:

  • Headers: Identify the sender, receiver, document type, and other key details. They provide routine and reference information.
  • Data Elements: Define specific data fields with associated codes and values. Data elements have names, lengths, data types, and formatting rules.
  • Transaction Sets: Comprise one or more data elements organized into a logical business transaction. For example, an invoice transaction set may include data elements for invoice number, date, line items, amounts, discounts, taxes, and payment terms.


Within each part, the ANSI X12 standards specify:


  • Segment identifiers: Unique 3-character codes that label different parts of the document.
  • Element identifiers: Unique 3- or 4-character codes that label specific data fields.
  • Code lists: Standardized sets of numeric or alphanumeric codes to populate data elements.

Using this structured format, ANSI X12 EDI services documents can transmit data in a predictable, repeatable manner. The structural consistency makes it easier for businesses to interpret and process transactions electronically without human intervention. It also enables automated data entry and exception handling.


Hierarchical levels and segments


There are four hierarchical levels in ANSI X12 standards – document, transaction set, segment, and data element. The highest level is the document which contains one or more transaction sets.

A transaction set represents a business event like a purchase order or invoice. It consists of multiple segments in a specified order.

A segment contains related data elements grouped by function. It begins with a three-character identifier and terminates with a segment terminator.

Finally, data elements contain specific pieces of information within a segment. They are identified by four character element identifiers.

Within a transaction set, segments are grouped into hierarchical levels to represent specific parts of a business document. For example, an invoice transaction set may have:

  • Header segments (BEG and UNH) at the top level.
  • Detail segments (LIN and QTY) at the second level, repeated for each line item.
  • Summary segments (TOT and CTT) at the third level.
  • Trailer segments (END) at the bottom level.

This hierarchical structure of interrelated segments makes ANSI X12 transaction sets human-readable and machine-processable. The segments contain properly tagged data elements that trading partners can interpret consistently.


Types of ANSI X12 standards


Different types of ANSI X12 standards define specific categories of electronic business documents. The most common types are:


  • Financial transaction standards – ANSI X12 EDI services cover transactions like payments, remittance advice, and funds transfer. Examples are the 820 payment orders and 835 healthcare payment and remittance advice standards.
  • Supply chain transaction standards – Used for transactions between suppliers, distributors, and manufacturers. Examples are the 850 purchase order and 856 shipping notice standards.
  • Health care transaction standards – Used for submitting electronic health care claims and other transactions between payers and EDI solution providers. Examples include the 837 healthcare claim standards and 278 healthcare eligibility inquiries. 
  • Resource transaction standards – Used for HR transactions between employers, payroll processors, and benefits EDI service providers. Examples are the 834 enrollment and maintenance and 899 benefits enrollment standards.
  • Transportation transaction standards – Used for transactions involving freight, shipping, and logistics. Examples are the 214 shipping instructions and 214 cargo manifest standards.


The structure and components of ANSI X 12 standards vary to meet the particular data needs of that transaction type. However, all ANSI X12 standards follow the same basic hierarchical design of documents, transaction sets, and segments. This consistency enables businesses to implement multiple ANSI X12 standards across different functional areas.


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Key Elements and Segments


Several key elements and segments are common across most ANSI X12 transaction sets. Understanding these standard components is essential for implementing ANSI X12 standards. Common elements include:

  • ID elements – Identify key parties like sender, receiver, reference numbers
  • DTM elements – Capture dates related to the transaction
  • N1/N3/N4 elements – Capture name and address for names and locations
  • TXI elements – Capture taxes related to the transaction
  • AMT elements – Capture amounts and related details
  • QTY elements – Capture quantities, units of measure, and related details


Common segments include:


  • GS – Functional group header that identifies the group of transaction sets
  • ST – Transaction set header that identifies the specific transaction and control numbers
  • BEG – Beginning segment that indicates the start of a transaction set
  • CUR – Currency information segment specifying the currency used
  • REF – Reference identification segment that specifies identifiers cross-referencing related transactions
  • AMT – Monetary amount segment specifying amounts and related details
  • QTY – Quantity information segment specifying quantity, units of measure, and related details
  • SE – Transaction set trailer that acknowledges the end of a specific transaction set
  • GE – Functional group trailer that acknowledges the end of a group of transaction sets.


These key elements and segments allow ANSI X 12 EDI standard transaction sets to capture the basic components needed for most business transactions, like amounts, quantities, dates, references, and identifiers. Understanding how they’re used provides a foundation for mapping your data to ANSI X12 standards.


Message Structure and Syntax in ANSI X12


The ANSI X12 standards define a consistent structure and syntax for electronic business documents. This includes specific rules for:

  • Segment identification: Each segment begins with a three-character code to identify its purpose within the transaction set. These codes are unique and standard across ANSI X12.
  • Data element identification: Within each segment, data elements are identified by four character codes that indicate their meaning and position.
  • Delimiters: Specific characters are used as delimiters to separate segments, data elements, component values, and repeats. The most common are asterisk (*) and tilde (~).
  • Codes: Standardized code lists are used to populate data elements with predefined values. These ensure consistent interpretation across trading partners.
  • Lengths: Fixed length (FL) and variable length (VL) are used depending on the data type. FL data elements must adhere to the specified length.
  • Component identification: Some data elements have components that are identified with qualifiers to explain their meaning.
  • Repetition separators: Symbols indicate the repetition of segments or data elements to capture multiple instances within a transaction.
  • Case: ANSI X12 is case insensitive, so uppercase and lowercase letters are interchangeable.


This structured syntax allows ANSI X12 transactions to be both human-readable and machine-processable. The standard elements and order make it easy for computers to identify, extract and validate data while still presenting a logical flow for humans. The consistency in syntax across all ANSI X12 standards also allows for the reuse of mapping, parsing, and validation rules. Maintaining this structured syntax is essential for successfully exchanging ANSI X12 documents.


Data Types and Code Lists in ANSI X12


ANSI X 12 EDI standard defines specific data types and code lists for representing different kinds of information in electronic documents.

Data types developed by top EDI service providers in USA include:

  • Numeric: Used for quantities, amounts, counts, codes, and identifiers. Numbers can be integers, decimals, or percentages.
  • Alphanumeric: Uses letters and numbers. Used for things like names, descriptions, part numbers, and identifiers.
  • Date: Captures dates in a standard format of CCYYMMDD.
  • Time: Captures time in a standard format of HHMM.
  • Indicator: A single character, Y or N, to indicate yes/no or true/false.

Code lists specify standardized sets of codes to populate data elements for things like:

  • Document types (invoices, orders, advisories)
  • Transaction reasons (new, change, cancellation)
  • Units of measure (hours, kilograms, meters)
  • Countries
  • Currencies
  • Roles (buyer, seller, ship-to, bill-to)
  • Payment formats (check, wire transfer, credit card, EFT)
  • Industry codes


Why use Code list and data types?

Using standard code lists and data types ensures consistency when exchanging ANSI X12 documents. Businesses can interpret dates, numbers, codes, and indicators in a uniform way, reducing errors and ambiguities. It also enables automated validation of data elements, data segmentation within files, and rules-based routing. Though some code lists are specific to an industry, the use of generic data types and centralized code lists still facilitates data consistency across organizations.


ANSI X12 Versioning and Updates


ANSI X12 standards are periodically updated to accommodate changes in business processes and technologies. Each version contains modifications and improvements to the document structures, code lists, and implementation guides. The current latest version for new developments is 005010 though older versions like 004010 are still used.


When a new version of an ANSI X12 standard is released, trading partners must coordinate to transition. They must agree on a conversion timeline, update mapping rules and configuration, test file exchanges, and handle exceptions. Employees may need training on the changes in data elements, codes, and usage. Organizations must also update documentation, references, and workflows to reflect the new version.


Migrating to a new ANSI X12 version can be time-consuming and costly but provides benefits like increased efficiency, the ability to handle new transactions, and the use of expanded code lists. Proper planning, change management, and testing are critical for a smooth transition between versions of ANSI X12 standards.


Industries and Applications of ANSI X12 standards


Many industries and business functions use ANSI X12 standards to automate business processes through electronic data interchange.

Common applications of ANSI X12  include:

  • Supply chain management – Purchase orders, shipping notices, invoices, advanced shipment notices
  • Finance – Payment instructions, remittance advice, funds transfers
  • Healthcare – Insurance claims, referrals, eligibility checks, pre-authorizations
  • Human resources – Employee enrollment, payroll submissions, benefits management
  • Transportation – Booking requests, cargo manifests, customs declarations
  • Inventory management – Receiving notices, lot tracking, product specifications
  • Government agencies – Tax filings, customs forms, social security statements


ANSI X12 standards help businesses in these areas simplify manual data entry, reduce paper usage, speed up document processing, lower costs and improve accuracy. Electronic data interchange using ANSI X12 enables greater connectivity between businesses and their suppliers, customers, EDI solution providers, and partners, enhancing overall efficiency. Though initially developed for financial transactions, ANSI X12 standards now support the data interchange needs of many different industries and functions.


Advantages of ANSI X12


There are many benefits to using ANSI X12 standards for electronic data interchange between businesses. Some key advantages include:

  • Improved efficiency – ANSI X12 automates routine data exchanges, reducing manual data entry, paper handling, and human errors. This saves time and resources.
  • Lower costs – Electronic documents cost less to process than physical documents. Also, automating document exchanges using ANSI X12 lowers overall business expenses.
  • Higher accuracy – Consistent ANSI X12 document structures and code lists reduce ambiguities and misinterpretations, leading to more accurate data and transactions.
  • Increased connectivity – ANSI X12 enables easy integration between systems, allowing businesses to connect with more suppliers, customers, and partners.
  • Compatibility – Because ANSI X12 is a widely used standard, most businesses, industries, and software solutions support it, making data exchange possible between diverse organizations.
  • Scalability – ANSI X12 provides standards for many types of documents, allowing businesses to automate more processes and data flows as their needs grow.
  • Flexibility – ANSI X12 offers options for data types, formats, transmission methods, and implementation that allow for customization to specific business needs.


Adopting ANSI X12 standards provides businesses with a foundation for electronic data interchange that can improve their supply chains, internal processes, and customer relationships through more seamless connectivity, streamlined information flows, and reduced costs.


Challenges and Limitations of ANSI X12



  • ComplexityANSI X 12 EDI standard documents can be complex with many segments, elements, codes, and repetitions. This makes initial setup and mapping data tricky.
  • Cost – There are often costs involved for software, consultants, testing, and training to implement ANSI X12 properly.
  • Inflexibility – ANSI X12 documents have a rigid format that does not always map perfectly to internal data structures, requiring data mapping and transformations.
  • Compatibility issues – Even though ANSI X12 is a standard, differences in versions, implementations, and configurations can still cause mismatches between trading partners.
  • Limitations of code lists – ANSI X12 code lists may not cover all possible values or options within an organization’s processes.
  • Governance needs – Using ANSI X12 requires managing master data, code lists, versions, and configuration across all trading partners.
  • Resistance to change – Migrating processes to an electronic data interchange model requires organizational change management to ensure adoption and success.



  • Difficulty: ANSI X12 documents can be complicated with numerous segments, fields, codes, and repeats. Setting up and mapping data to these structures is challenging.
  • Expense: There are usually costs for software, consultants, testing, and training to properly implement ANSI X12.
  • Rigidity: ANSI X12 documents have a fixed format that doesn’t always match internal data, requiring transformations.
  • Inconsistency: Even though ANSI X12 is a standard, differences in versions, implementations, and configurations between partners can still cause mismatches.
  • Coordination: Using ANSI X12 requires managing shared data, codes, versions, and configurations with all trading partners.
  • Errors: ANSI X12 documents have little flexibility for handling errors, so exceptions must be handled manually.
  • Maintenance: ANSI X12 maps, configurations, and code lists require ongoing maintenance to work with partners.
  • Testing: Trading partners must frequently test ANSI X12 document exchanges to identify and correct issues.

While these challenges can be mitigated with the right planning, testing, and change management, they do require upfront effort and ongoing management when implementing ANSI X12. But for most organizations, the benefits of automation, efficiency gains, and connectivity outweigh the challenges when properly executing ANSI X12 standards.


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ANSI X12 standards provide businesses with a useful framework for exchanging electronic documents and data in a consistent format. The standards define structures, segments, codes, and data types to facilitate interoperability between different systems and organizations. Though implementing ANSI X12 comes with some challenges, the benefits of automation, efficiency, and connectivity make it worth the effort for improving supply chains, business processes, and customer relationships. With proper planning, governance, and change management, most businesses can leverage the ANSI X 12 EDI standard to enhance how they exchange and utilize the information with their partners.




What is the ANSI X12 format?


ANSI X12 format refers to the specific structures, syntax, and rules defined by ANSI X12 standards for creating and sending electronic business documents. It defines segments, data elements, codes, delimiters, and layouts to create standardized business documents like purchase orders, invoices, and shipping notices. It specifies how information should be organized within these documents so they can be transmitted, parsed, and processed electronically without errors across different systems. ANSI X12 format allows businesses to automate manual data handling and exchange documents in a uniform, machine-readable manner that can be interpreted consistently by organizations and software applications. Implementing the ANSI X12 format enables electronic data interchange between companies.


What is the use of ANSI X12 ?


The main uses of ANSI X12 standards are to enable electronic data interchange and automate business processes between organizations. By exchanging electronic documents in ANSI X12 format, businesses can:


  • Reduce manual data entry and paperwork
  • Improve the speed of processing documents
  • Lower costs by avoiding printing, mailing, and re-keying data
  • Reduce errors through consistent, standardized formats
  • Increase connectivity with suppliers, customers, and partners
  • Integrate disparate systems that support ANSI X12
  • Consolidate data from multiple trading partners
  • Automate routine tasks like order processing and payments


By adopting ANSI X12 standards, organizations can streamline document-based workflows, improve supply chain management and boost overall efficiency. ANSI X12 allows businesses to exchange and utilize information with their partners in a faster, more accurate, and cost-effective manner through electronic data interchange.


What is the difference between ANSI X12 and EDI X12?


ANSI X12 and EDI X12 are essentially the same things – they both refer to the set of standards for Electronic Data Interchange developed by the American National Standards Institute. ANSI X12 and EDI X12 define the document structures, data elements, codes, and syntax for systematically transmitting business data between organizations.


The main difference is in terminology. While ANSI X12 is the formal name for the standards as they are published by the ANSI organization, EDI X12 is a more generic term that is often used when referring to the implementation and use of these standards for EDI The standards themselves and their purpose remain the same – they exist to facilitate the electronic exchange of information between businesses. So in practice, ANSI X12 and EDI X12 can be used interchangeably to refer to the same set of EDI standards.


What is the ANSI standard for EDI?


The ANSI X12 standards are the main ANSI standards for electronic data interchange (EDI). ANSI X12 defines the document structures, data elements, codes, and syntax for systematically transmitting business data between organizations.


The ANSI X12 standards cover a wide range of common business documents like purchase orders, invoices, shipping notices, payments, and human resource forms. The standards specify the format and layout that these documents must follow so they can be electronically exchanged, processed, and understood consistently.


By complying with ANSI X12 standards, businesses can engage in electronic data interchange with other companies that also follow the same standards. This allows the automation of routine data transfers and information exchanges between organizations.