Make your emissions data stand up to scrutiny

Starting out with your first carbon footprint, or refining years of data? Either way, the credibility of your greenhouse-gas (GHG) numbers matters. Reliable, verified information builds trust with customers, regulators and supply-chain partners – and helps you make confident decisions. Here’s how to find the right type of independent check for your business.

Why independent checks matter

Independent reviews give confidence that your figures are robust and transparent. For manufacturers, they can reveal data gaps in energy use, fuel consumption or process emissions; reduce the risk of overstated “carbon-neutral” claims; and strengthen credibility with clients, boards and export markets.

A third-party perspective adds objectivity and helps demonstrate integrity – especially useful when bidding for contracts or supplying international brands that ask for evidence of sustainability performance.

Choosing the right GHG evaluation approach

Term	Use for:	What is reviewed (include timeframe)	Outcome
Verification	Public reporting or disclosure where independent checks are required. Credibility for boards, investors, or regulators.	Historical GHG data, calculation methods, and processes. Timeframe: Past or current reporting period.	Independent statement of assurance – limited (regulatory) or reasonable (investor-grade).
Validation	Setting or updating emissions reduction targets. Testing future assumptions or pathways.	Assumptions, models, and methods for projections. Timeframe: Future targets or scenarios.	Opinion on whether your approach and assumptions are sound and achievable.
External review	Independent feedback before verification or disclosure. Checking inventory or scope 3 estimates.	Data, methods, and reporting approach. Timeframe: Past or current data.	Informal feedback to improve quality; no formal assurance.
Assurance	Building confidence in verified data for regulated or investor reporting. Choosing limited or reasonable assurance.	Verified historical information. Timeframe: Past reporting period.	Formal statement confirming confidence level in verified data.
Certification	Claiming carbon neutrality or joining programmes (e.g. Toitū, Ekos, Climate Active). Public recognition of verified results.	Verified data, reduction plans, and progress updates. Timeframe: Ongoing, periodic review.	Certification confirming compliance (e.g. carbon neutral, net zero).

Verification, validation, assurance and certification – what they mean

Verification looks backward. It checks whether your reported GHG data – like fuel used in boilers or forklifts, electricity for production lines, refrigerants and process emissions – is accurate and follows recognised standards.

Verified data supports sustainability reporting and tender requirements.

Validation looks forward. It assesses whether the data, methods and assumptions behind your planned emission reductions or targets are credible and achievable.

For example, if you plan to electrify furnaces, recover waste heat or improve process efficiency, validation assesses whether those assumptions are realistic and based on sound information before you announce them.

Both processes follow ISO 14064-3:2019, the international standard for verification and validation.

Assurance is the formal statement that follows verification. It’s issued by the verifier and provides confidence that your emissions data has been independently reviewed to a recognised standard.

Limited assurance gives a moderate level of confidence based on a less detailed review. Reasonable assurance involves deeper testing and provides higher confidence.

Certification goes a step further and applies when you make public claims – for example, “carbon-neutral operations” or “low-carbon product.”

It’s part of a formal scheme run by a government, industry body, or programme such as Toitū and Ekos in New Zealand, or Climate Active in Australia.

It generally combines verified data with a documented plan how you’re going to achieve your carbon emission reductions and regular reviews to confirm that you’re on track.

Recommendations for New Zealand manufacturers

Review emissions annually with an experienced third party
Regular external reviews help keep your data accurate and highlight opportunities to reduce energy, fuel or material use – areas that often translate to cost savings in manufacturing operations.
Choose verification for robust, credible data
Verification provides stronger evidence than internal checks and builds confidence with customers, investors and regulators. Start small if you’re new to carbon reporting – an informal review can prepare you for full verification later.
Validate your reduction targets
Before you announce emissions goals, test your assumptions – especially if your plans rely on changes to manufacturing processes, fuel switching or electrification.
Set a Science Based Target (SBT) once your data is verified
SBTs give you a clear, credible pathway for ongoing emissions reduction, aligned with global best practice.
Stay across changing regulations and expectations
New Zealand’s rules on climate and carbon reporting are evolving, and large customers are asking for more reliable data from their suppliers. By checking and improving your data now, you’ll be ready for new requirements and save time and cost later.
Choose credible certification schemes and be transparent about their scope
If you’re making public carbon claims – for example, about carbon neutrality – make sure they’re backed by verified data and reference recognised standards such as ISO 14064-3.
Treat verification as an improvement tool
Beyond compliance, verification strengthens data systems and often uncovers efficiency gains that save both money and emissions.