Audit Trail

What EmWise records per job

Every emission calculation in EmWise produces an immutable audit record. The following information is stored for each job submission:

Job record

Field	Description
id	System-generated UUID
organization_id	The organisation that submitted the job
client_id	Client linked to the job (if provided)
origin	Origin location as submitted
destination	Destination location as submitted
reference_number	Your TMS reference (if provided)
distance	Distance in km (if provided)
departure_date	Departure date/time (if provided)
arrival_date	Arrival date/time (if provided)
cargo_weight_tonnes	Cargo weight (if provided)
vehicle_class_id	FK to the vehicle class used
created_at	Timestamp of submission

Calculation record

Field	Description
id	System-generated UUID
job_id	FK to the parent job
calculation_method	Always method_1 for NGER Method 1
transport_mode	Transport mode code used
fuel_type	Fuel type code used
fuel_quantity	Fuel consumed in kL (as submitted)
energy_content	Calculated energy consumed in GJ
co2_emissions	CO₂ component in t CO₂-e
ch4_emissions	CH₄ component in t CO₂-e
n2o_emissions	N₂O component in t CO₂-e
scope1_emissions	Total Scope 1 in t CO₂-e
scope3_emissions	Total Scope 3 in t CO₂-e
total_emissions	Scope 1 + Scope 3 in t CO₂-e
emission_factor_id	FK to the exact emission factor row used
reporting_year	NGER reporting year attributed to this job
vehicle_class_id	FK to the vehicle class (duplicated for query efficiency)
submitted_by_key_name	Name of the API key used to submit (API submissions only)
created_at	Timestamp of calculation

The emission_factor_id foreign key is the critical audit link — it points to the exact row in the emission_factors table that was used, including its co2_factor, ch4_factor, n2o_factor, and energy_content values at the time of calculation.

Report snapshot immutability

When an NGER report is generated, EmWise creates a snapshot of all emission calculations within the reporting period. This snapshot is a point-in-time aggregate — the figures it contains do not change even if:

• New jobs are added to the same reporting period after the snapshot is taken
• Emission factor values are updated in future years
• The underlying calculation records are amended

This means a report generated on 30 June 2025 for the 2025 NGER reporting year will always show the same figures as the day it was produced.

Responding to a CER audit

If the Clean Energy Regulator audits your NGER submission, EmWise provides the following audit evidence:

1. Calculation-level traceability For any reported emission figure, EmWise can show the underlying jobs and calculations that contributed to it, including the exact emission factor used (with its source reference year and NGER Determination division).

2. Factor provenance Each emission factor row in EmWise references the NGER (Measurement) Determination by reporting year and vehicle class. The factors stored match Schedule 1 of the Determination as published by the CER.

3. Data lineage Jobs submitted via the API include the name of the API key used (submitted_by_key_name), enabling you to trace a calculation back to the source system that submitted it.

4. Immutable history Calculations and jobs are append-only. Corrections are made by submitting replacement jobs (with a new reference number), not by modifying existing records. The original record and the correction are both visible in the audit log.

Recommended record-keeping practices

• Keep your source fuel records (fleet card statements, supplier invoices) for at least 7 years as required by NGER.
• Use the reference_number field to link EmWise job records back to your TMS or ERP records.
• Export a copy of the NGER report snapshot to your document management system at the end of each reporting period.
• If you correct a historical job (e.g. wrong fuel quantity), submit a negative adjustment job and document the reason.