AVETMISS 101 – NAT Files: The Building Blocks of Student Data

What a NAT File Represents

A NAT file is a standardised output of data stored in your Student Management System. When AVETMISS data is generated, the system extracts information from its database and places it into a set of plain text files that follow strict national specifications.

Each NAT file contains records where every value appears in a fixed position and length. Validation is not only about whether the correct value exists, but whether that value appears exactly where the AVETMISS standards expect it. Because of this structure, even small data issues can surface later as validation errors.

Why There Are Multiple NAT Files

AVETMISS data is intentionally divided across multiple NAT files, with each file responsible for a specific category of information. Some files define organisational and setup data, others define student information, and others record training activity and outcomes.

Rather than repeating the same information in multiple places, AVETMISS relies on relationships between files. A value defined once in a foundational file is reused and referenced elsewhere. This design keeps national data consistent but also means that errors in early files affect everything that follows.

How Data Flows Into NAT Files

All AVETMISS data begins as operational data inside your Student Management System. Programs, subjects, student records, enrolments, dates, outcomes, and funding information are entered once and reused across the system.

When AVETMISS files are generated, the system does not create new data. It simply repackages existing data into the required NAT file formats, applying the rules defined in the AVETMISS standards. This means that NAT files do not correct errors — they expose them.

The Building Block Concept

AVETMISS reporting is built in layers. The files from NAT00010 through to NAT00100 form the foundation of the submission. These files define the background data that everything else relies on, including the RTO, delivery locations, programs, subjects, students, contact details, disability information, and prior education.

Sitting on top of this foundation are the two outcome files:

• NAT00120 – Student Training Activity

• NAT00130 – Program Completed

These files do not operate independently. They rely entirely on the accuracy and consistency of the earlier NAT files. If the foundation is weak, errors will surface in the outcome files.

Why Errors Appear in NAT00120 and NAT00130

NAT00120 is where all earlier setup becomes reported training activity. It brings together students, programs, subjects, locations, dates, outcomes, and funding into a single record per subject enrolment. Because it references so many other files, it is often where errors multiply.

In most cases, NAT00120 is not the source of the problem — it is where upstream issues are revealed. NAT00130 behaves in a similar way for program completions, relying on the same student and program definitions.

Understanding this dependency is critical before analysing NAT00120 or NAT00130 errors.

Understanding the Fixed-Width Format

NAT files use a fixed-width format, meaning each field starts at a specific character position and has a defined length. Fields are not separated by commas or tabs. Validation depends on both the value and its exact position in the file.

This is why accurate setup inside your Student Management System is so important. When data is correct at the source, it appears correctly positioned in the NAT files.

Viewing NAT Files for Understanding

While NAT files can be opened in basic text editors, specialised editors make learning and troubleshooting much easier by displaying character positions and line numbers. Viewing NAT files helps you understand how data is structured and where validation issues originate.

However, NAT files should never be edited manually. Any corrections must be made in the Student Management System, followed by regeneration and revalidation of the files.

Key Takeaway Before Moving On

NAT files are not separate pieces of data — they are structured outputs of the same underlying system information. When foundational data is set up correctly, AVETMISS reporting becomes predictable and far easier to validate.

Understanding how NAT files connect is the essential first step before working with NAT00120 – Student Training Activity, where those relationships become visible.

Outcome of This Lesson

By the end of this lesson, you should be able to:

• Explain what a NAT file represents

• Describe how AVETMISS data is structured across multiple NAT files

• Understand how data flows from a Student Management System into NAT files

• Recognise why NAT00120 and NAT00130 depend on earlier files

• View NAT files confidently for learning and troubleshooting purposes