How to Choose a Reputable GHG Inventory Consultant: 7 Criteria [2026]

Choosing a reputable greenhouse gas (GHG) inventory consultant should be based on 7 criteria: ISO 14064 expertise, experience in your specific industry, the ability to support you through verification, transparent scope and pricing, a calculation platform/tools, commitment to meeting submission deadlines, and evidence of real projects. A firm that is strong in verification and has industry experience will help your report pass review the first time — avoiding rework and compliance risk.

From 25 September 2026, the list of facilities required to conduct an inventory covers 2,441 facilities under Decision 42/2026/QD-TTg. Many businesses are looking for a consultant for the first time and receiving quotes that differ several-fold. This article provides a set of criteria and a checklist to help you choose the right firm, rather than the cheapest one.

Why does choosing the right consultant matter?

Because GHG inventory reports are reviewed by regulators and you may be asked to provide explanations. A firm that is weak on methodology will produce inconsistent data, lack justification for emission factors, or miss emission sources — leading to rework, missed deadlines, and the risk of penalties. The cost of hiring the right firm is usually offset by avoiding these consequences.

7 criteria for choosing a reputable GHG inventory consultant

• Standards-based expertise: applies ISO 14064-1, the GHG Protocol and guidance from the relevant line ministry; clearly states the sources of emission factors.
• Relevant industry experience: has worked for companies in your sector (textiles and garments, food, cement, steel…) — each industry has its own specific emission sources.
• Verification support: stays with you while the report is reviewed, rather than "hand over the report and walk away".
• Transparent scope & pricing: clearly states which Scopes are covered (1, 2, 3) and how many facilities/emission sources — avoid vague quotes.
• Platform & tools: has calculation tools/a platform that make data traceable and reusable for the next period.
• Timeline commitment: guarantees the report is submitted on time (before 31 March, on a 2-year cycle).
• Real-world evidence: case studies, client references, and a team of certified experts.

Figure 1: 7 criteria for choosing a reputable GHG inventory consultant

Checklist of questions to ask before signing a contract

1. Which standards do you apply, and where do you source emission factors from?
2. Have you conducted inventories for companies in our industry?
3. Which Scopes does the quote cover, how many facilities/sources, and does it include data collection & checking?
4. Do you provide support when regulators or the verification body request explanations?
5. What is your timeline commitment, and what is your responsibility if the report does not pass review?
6. Can the data and report be reused for the next inventory period?

Workers on site checking steel materials

How should businesses newly subject to the requirement get started?

First, confirm whether you are on the list of 2,441 facilities required to conduct an inventory under Decision 42/2026, then set a budget based on benchmark GHG inventory costs by industry, and choose a firm using the 7 criteria above. See also the comprehensive guide to GHG inventories to understand the process and roadmap.