Scope 1, 2 and 3 Emissions: What Data You Actually Need to Collect

Most contractors and suppliers across Australia know there are three scopes of emissions. Far fewer know exactly which documents to pull out of a filing cabinet to calculate them.

This article does not define what the scopes are. It walks through what data you actually need to collect for each one, using two real-world contractor scenarios: a civil contractor in the Hunter Valley, New South Wales, and a maintenance services provider in the Pilbara, Western Australia. At the end, you will see what a completed three-scope summary looks like when pasted into a tender response.

Why this matters in 2026

Scope 3 reporting is now mandatory in Australia for Group 1 entities. Group 2 entities, mid-market businesses with revenue over $50 million, are captured from 1 July 2026. Even if your business does not meet the Group 2 threshold, your major clients almost certainly do. That means they will be asking you for Scope 1 and 2 figures, and increasingly Scope 3 data, as part of their own supply chain disclosure obligations under AASB S2.

For contractors responding to pre-qualification forms, Scope 3 supplier questionnaires, or government tenders under equivalent state procurement frameworks, having documented emissions data is no longer optional.

The two scenarios

Scenario A: Hunter Valley civil contractor
Hunter Civil is a mid-size civil contractor based in Cessnock, NSW. They operate in the Hunter Valley coal and infrastructure corridor, running owned earthmoving and civil plant, a fleet of light vehicles, and leasing a workshop and yard. They employ 38 staff and regularly tender to mining majors and NSW government infrastructure bodies.

Scenario B: Pilbara maintenance services provider
Pilbara Maintenance Services (PMS) operates out of Karratha, WA. They provide shutdown and turnaround maintenance to LNG facilities, iron ore processing plants, and port infrastructure across the Pilbara. They operate a mix of owned vehicles, chartered site transport, and hire specialised equipment for each shutdown.

Scope 1: Direct emissions

Scope 1 covers emissions from sources your business owns or directly controls. For most contractors, this is the largest emissions category and the most straightforward to calculate.

What qualifies as Scope 1

• Diesel and petrol combustion in owned plant, equipment, and vehicles
• Natural gas or LPG combustion in workshops or site facilities
• Refrigerant leaks from air conditioning systems in vehicles, site offices, and depot buildings
• Any fuel burned on-site in equipment your business owns or operates

The documents you need

Data source	What to collect	Period
Fuel card statements	Litres by fuel type (diesel, petrol, LPG) per vehicle or asset	Full financial year
Fuel supplier invoices	Same as above, use if fuel cards are incomplete	Full financial year
Bulk diesel tank records	Pump-out logs from on-site storage tanks	Full financial year
Refrigerant service records	Kilograms added and refrigerant type (R-410A, R-32, etc.)	Full financial year
Gas bills	Cubic metres consumed, if applicable	Full financial year

Hunter Civil: Pulls 12 months of fuel card statements across earthmoving plant, trucks, and light vehicles. Their depot has a split-system air conditioner with an annual service record showing refrigerant top-up.

Pilbara Maintenance Services: Fuel consumption is split across owned vehicles and a diesel generator used on remote shutdown sites. Refrigerant data is collected from fleet service records across their Karratha vehicle pool.

Calculation method

Use the current edition of the Australian Government's National Greenhouse Accounts (NGA) Factors, updated annually by the Department of Climate Change, Energy, the Environment and Water. These are the accepted emission factors for all Australian operations.

For diesel combustion, multiply total litres by the NGA kg CO₂-e per litre factor for diesel. Repeat for each fuel type. Apply the relevant Global Warming Potential value for each refrigerant type.

Scope 2: Purchased electricity

Scope 2 covers indirect emissions from electricity purchased from the grid. The emissions occur at the power station, but are attributed to the buyer.

What qualifies as Scope 2

• Grid electricity consumed at any premises your business leases or owns: depots, workshops, offices, site amenities
• Does not include electricity generated by on-site solar (this offsets Scope 2 but is not itself Scope 2)

The documents you need

Data source	What to collect	Notes
Electricity bills	Kilowatt-hours (kWh) consumed per billing period	Collect all bills for all premises for the full year
NMI (National Meter Identifier)	Confirms which meter and premises the bills relate to	Printed on every electricity bill
Lease agreements	Confirms which premises you are responsible for	Needed if multiple tenants share a building

Hunter Civil: Two premises in Cessnock: a main workshop and yard, and a small project office in Singleton. Total annual electricity consumption is collected from both accounts.

Pilbara Maintenance Services: Their Karratha depot is grid-connected. Remote shutdown sites typically run on diesel generators (captured under Scope 1) rather than grid power. Only the permanent Karratha premises is counted in Scope 2.

Calculation method

Multiply total kWh by the state-specific grid emission factor from the NGA Factors document. NSW and WA have separate grid factors. Do not use a national average.

Two accepted methods exist under the GHG Protocol:

• Location-based: Uses the average grid emission factor for your state. Most common for Australian SME tenders.
• Market-based: Uses a supplier-specific or contractual factor. Relevant only if you have purchased GreenPower or a renewable energy product.

For most tender responses in Australia, location-based is expected and sufficient.

Scope 3: Indirect value chain emissions

Scope 3 covers all other indirect emissions that occur upstream or downstream of your own operations as a result of your activities. The GHG Protocol defines 15 Scope 3 categories. Most Australian contractors do not need to report all 15.

The categories most relevant to contractors and maintenance service providers are:

Category	Relevant to contractors?	Data needed
Cat 1: Purchased goods and services	Sometimes, if significant materials are procured	Supplier invoices, spend data
Cat 3: Fuel and energy-related activities	Yes, upstream extraction of fuel you burn	Derived from Scope 1 fuel data using NGA upstream factors
Cat 4: Upstream transportation and distribution	Sometimes, if you freight significant materials or equipment	Freight invoices, tonnes x km
Cat 6: Business travel	Yes, flights, accommodation, rental vehicles	Travel booking records, credit card statements
Cat 7: Employee commuting	Optional, rarely required in tenders	Staff numbers, suburb data, commute estimate

The critical distinction: hired plant

This is where many contractors misclassify emissions. The rule is straightforward:

• If your operator is on the machine, it is Scope 1 regardless of who owns the equipment
• If the hire company's own staff are operating the equipment, it is Scope 3 Category 1

Document this distinction clearly in your methodology. Procurement auditors from mining majors will check it.

Hunter Civil: Regularly hires excavators and graders for peak projects. Their own plant operators are always on the machines, so hired plant fuel is captured under Scope 1. They report Scope 3 for business travel (flights between Cessnock and Brisbane for client meetings) and upstream fuel emissions derived from their Scope 1 diesel figure.

Pilbara Maintenance Services: During shutdowns, they charter light buses to move their crew between Karratha and remote sites. The charter company provides the drivers. This is Scope 3 Category 4. PMS also reports Category 6 for flights between Perth and Karratha for senior supervisors, and Category 3 upstream fuel emissions derived from their diesel figure.

Documents for the most common Scope 3 categories

Business travel (Category 6):

Data source	What to collect
Flight booking records	Origin, destination, class of travel for each trip
Accommodation records	Nights stayed (spend-based estimate is acceptable if granular data is unavailable)
Rental vehicle records	Days hired, vehicle class

Chartered or contracted transport (Category 4):

Data source	What to collect
Transport provider invoices	Passenger-kilometres or tonne-kilometres
Provider emissions data	Some contractors can supply an emissions figure per trip on request

Upstream fuel and energy (Category 3): No additional documents required. This is calculated from your Scope 1 fuel data using upstream extraction and refining factors from the NGA Factors document.

What a completed tender summary looks like

This is the format both Hunter Civil and PMS would use in a pre-qualification form or tender response. Insert your verified figures against each line.

Scope	Description	Emissions (tCO₂-e)
Scope 1	Direct emissions: diesel, petrol, LPG, refrigerants (owned and operated fleet and plant)	[verified figure]
Scope 2	Purchased electricity: all leased premises, location-based method	[verified figure]
Scope 3	Business travel (Cat 6), chartered transport (Cat 4), upstream fuel and energy (Cat 3)	[verified figure]
Total		[verified figure]

Emission factors sourced from Australian Government NGA Factors, current edition. Scope 3 reporting covers categories material to operations. Full methodology notes available on request.

Common mistakes that will get your data rejected

Using the wrong NGA Factors edition. Factors are updated each December. Using the 2022 edition in a 2025 submission is an easy audit flag.

Inconsistent reporting boundary year on year. If you measure the Karratha depot in year one and exclude it in year two, your emissions appear to fall without any operational change. State your boundary clearly and hold it.

No methodology statement. A number without a methodology is unverifiable. The one-paragraph statement above is the minimum acceptable standard for major mining company and government procurement.

Misidentifying scope boundaries for hired plant. Who operates the machine determines the scope, not who owns it.

What to do with this data

A documented, methodology-backed three-scope summary allows you to:

• Answer pre-qualification forms and Scope 3 supplier questionnaires with confidence
• Use the baseline year on year to demonstrate a reduction trend, which is increasingly scored in tender evaluations
• Build toward an ISO 14064-aligned inventory if a client requests formal verification