Last updated: 6 October 2026
A carbon inventory compiles a company's greenhouse gas emission sources, activity data and calculation results for a defined period and boundary, answering “where do emissions come from, and how much is emitted?” Before starting, confirm who will receive it: a regulator, a customer or an internal team. Different purposes require separate confirmation of boundaries, reporting and verification requirements.
What Is a Carbon Inventory, and How Does It Differ from a Product Carbon Footprint?
A corporate carbon inventory covers an organisation; a product carbon footprint follows the life cycle of a good or service. The former shows the company's emissions profile, while the latter provides emissions information for an individual product. They cannot directly replace each other.
| Comparison | Organisational carbon inventory | Product carbon footprint |
|---|---|---|
| Subject of assessment | Organisational boundaries such as companies and facilities | The product system of a specific good or service |
| Common standards | ISO 14064-1, GHG Protocol | ISO 14067 |
| Key data | Emission sources, energy and other applicable activity data within the boundary | Data on raw materials, manufacturing, distribution, use and disposal |
| Where to start | Establish a corporate emissions inventory first | Then calculate life-cycle emissions for each product |
Conceptual references: ISO 14064-1 and ISO 14067. If a customer is asking about an individual product, continue with product carbon footprint calculation and data preparation to agree on the required deliverable first.
Which Businesses Must Conduct a Carbon Inventory?
First check the industries, processes and thresholds announced by Taiwan's Ministry of Environment. Company size or listing on the Taiwan Stock Exchange (TWSE) or Taipei Exchange (TPEx) alone is not sufficient. Statutory inventories, carbon fees and customer requirements have different conditions; meeting one does not mean the other obligations are identical.
Under the announcement amended on 22 February 2024, the first batch includes designated processes such as power generation, steelmaking, petroleum refining, cement, semiconductors and TFT-LCD, as well as emission sources whose facility-wide annual fossil fuel combustion emissions reach 25,000 metric tonnes CO₂e. Process-based coverage must still be checked against the conditions in the annex; an entire industry should not automatically be treated as regulated. From 1 January 2023, the second batch covers manufacturers whose combined direct fossil fuel combustion emissions and indirect emissions from electricity use reach 25,000 metric tonnes CO₂e.
The effective date for the second batch can also be checked against the Ministry of Environment's announcement summary; historical reporting deadlines must still be read separately from current deadlines.
In addition, the expanded inventory announcements and industry guidance cover qualifying service businesses, transport businesses, hospitals, higher education institutions and manufacturers. Coverage for these entities cannot be determined solely from the two batches above. For detailed registration and verification schedules, see the greenhouse gas inventory registration guide.
Carbon fee coverage must be checked separately under Article 3 of the Regulations Governing the Collection of Carbon Fees: it applies to electricity and gas suppliers and manufacturers with emission sources designated for inventory registration and verification, whose facility-wide combined annual direct and electricity-related indirect emissions reach 25,000 metric tonnes CO₂e. If you receive a customer questionnaire, request the calculation standard, year, boundaries and verification requirements before scheduling work, to avoid delivering an inventory that does not serve its intended purpose.
How to Conduct a Corporate Carbon Inventory: Boundaries, Sources, Calculation, Reporting and Verification
Organise the work into five stages: boundaries, sources, calculation, reporting and verification. Define the scope before collecting data and calculating emissions. This sequence follows the Ministry of Economic Affairs' 2025 Corporate Net-Zero Action Handbook; the deliverables below can help allocate internal responsibilities.
| Stage | Work to complete | Recommended records and deliverables |
|---|---|---|
| Boundaries: confirm boundaries | Confirm the organisation, facilities and inventory period | Boundary description, site list and responsible contacts |
| Sources: identify emission sources | Identify combustion, process, fugitive and indirect emissions using the chosen methodology | Equipment list, emission source list and data sources |
| Calculation: quantify emissions | Check activity data, emission factors and units before calculating | Itemised calculations, factor references and original supporting records |
| Reporting: inventory and report | Compile results, methods, assumptions and reasons for exclusions | A consistent inventory and inventory report |
| Verification: review and verification | Conduct an internal review, then arrange third-party verification as required by obligations or the engagement | Correction records and applicable verification documents |
For the emission factor method, activity data multiplied by an emission factor is a useful starting point, but fuel calorific values, unit conversions and the global warming potentials of different gases must also be considered. Article 4 of the Regulations Governing Greenhouse Gas Emission Inventory, Registration and Verification also lists methods such as mass balance and direct monitoring; do not force the same multiplication formula onto every emission source.
Ask finance to provide electricity bills and purchasing records, facilities staff to confirm equipment and fuel data, and each site to explain data gaps. The inventory coordinator can then check years and units consistently. Trace original consumption data before discussing whether results are high or low, so calculations can be reproduced. For factor selection, see emission factor versions and applicable years; for emission classifications, see the explanation of Scopes 1, 2 and 3.
Is ISO 14064-1 Mandatory?
Choose the methodology based on the intended deliverable. Conducting a carbon inventory should not automatically be equated with obtaining a particular certificate. ISO 14064-1 is a standard for organisational quantification and reporting; GHG Protocol also provides corporate emissions inventory methods and guidance.
Statutory inventories should first follow Ministry of Environment regulations and inventory guidance, referring to applicable standards for matters not covered. A self-selected standard cannot replace legally required registration content. If customers or disclosure programmes impose additional requirements, list the standards, versions, organisational boundaries and reporting scope in a single requirements sheet and compare them item by item.
For choosing and combining the two approaches, read the comparison of ISO 14064 and GHG Protocol and GHG Protocol's official introduction to its standards. Defining the methodology before data collection is easier to manage than reclassifying results after calculations are complete.
In-House Work, Consultants or Software: How Should You Choose?
Allocate work according to internal capabilities and data readiness, rather than comparing only total quoted prices. In-house inventories, consulting support and software can be combined. The company still needs to confirm source data, while formal verification is performed by a third-party body.
| Approach | When to consider it | Questions to confirm |
|---|---|---|
| In-house preparation | An inventory methodology and data owners are already in place | Who checks boundaries, factors, formulas and supporting records? |
| Consulting support | Help is needed to determine scope or establish procedures | Does the service include training, on-site support and document revisions? |
| Software system | Data organisation and calculation need support | Test with your own data and check the results and their basis |
| Third-party verification | Regulations or customers require independent verification | Verification scope, applicable qualifications, schedule and responsibility for additional submissions |
When comparing prices, itemise internal staff time, consulting services, tools and third-party verification, and ask all providers to quote for the same year and boundary. If sites, data coverage or verification services differ, the lowest total price alone is not a sound basis for comparison. Use the carbon inventory system comparison to organise your criteria, then read the corporate carbon inventory system selection guide.
How Long Does a Carbon Inventory Take, What Does It Cost, and How Is Verification Arranged?
This page does not provide a universal timeline or fixed price. First identify sites, emission sources, data gaps and delivery requirements, then obtain a written schedule and itemised quotation. Schedule inventory completion, document corrections and third-party verification separately; figures generated by a system do not mean all work is complete.
Under Articles 6, 8 and 9 of the regulations, statutory inventory registration generally requires the previous year's inventory and report to be registered by 30 April each year. Entities designated for verification must use a verification body approved by the Ministry of Environment and upload verification results by 31 October. Confirm individual applicability and any separately approved arrangements against official requirements.
First check that inventory and report totals agree, each emission source is traceable to supporting records, factors have an applicable year, and the treatment of missing data is explained. When a third party requests corrections, update the inventory and report together and retain both versions so future staff understand why changes were made.
Next Step: Prepare Traceable Inventory Data
List the inventory purpose, year, sites and data owners before deciding what support you need. To evaluate tools, bring representative records such as electricity bills and fuel receipts to Sustaihub to learn about the DCarbon carbon inventory system.
DCarbon supports automated organisational carbon inventories, an AI document assistant, automatic route screenshots, AI inventory reports and product carbon footprint calculations, with support for ISO 14064-1 and ISO 14067. The system organises data and performs calculations; companies must review draft reports, and third-party bodies perform formal verification.
Carbon Management Fundamentals Series
Start with carbon inventories and explore regulations, costs and emissions reduction targets as needed:
- What Is a Carbon Inventory? 5 Steps, Regulatory Requirements and Tool Selection (this article)
- Greenhouse Gas Inventories: Which Businesses Must Register? Schedules, Guidance and Categories 1–6
- What Is Taiwan's Carbon Fee? Rates, Coverage, Calculations and Payment Schedule
- What Is a Carbon Footprint? Product Calculations, ISO 14067 and Emission Factor Lookup
- What Are Scopes 1, 2 and 3? The 15 Scope 3 Categories and ISO 14064-1 Mapping
- What Are Carbon Credits? Trading, Prices and Carbon Fee Offset Rules in Taiwan
- What Are Net-Zero Emissions? Taiwan's 2050 Pathway and First Steps for Businesses
- What Is Carbon Neutrality? ISO 14068-1, the 2026 Edition and Ministry of Environment Claims Guidance
