Overview

CarbonTool brings emissions accounting and reduction planning together, with distinct plans for single-entity firms, multi-unit businesses and large organizations. Its EU-hosted infrastructure and traceable data points are useful strengths for formal reporting, though access to full Scope 3 coverage starts with a paid plan.

Key features

Measurement and data collection

More than 200 emission-source templates pair methodologies and measurement units with emission factors, including databases from DEFRA, EPA, ecoinvent and ADEME. CarbonTool accepts manual entry, Excel and CSV files, AI uploads, API connections and SAF-T imports. This gives teams several ways to assemble activity data, while the templates provide a structured starting point; organizations should still ensure the chosen methodology and factors fit their reporting needs.

Each data point carries its source, unit, emission factor, quality level and audit trail. That provenance makes figures easier to trace and review than an inventory of unsupported totals.

Reporting and planning

A shared data backbone supports CSRD, VSME, GRI, CDP and ISSB reporting. CarbonTool also supports reduction targets and scenario planning that compares impact, cost and return. Together, those capabilities suit teams that need to connect emissions accounting with reduction decisions, not only produce an inventory.

Organizations can track subsidiaries, sites or business units separately, then consolidate them into a group inventory. That is a meaningful advantage for multi-entity reporting, but a single-entity business has less reason to pay for consolidation.

Connections and data residency

Customers can connect systems through an API or MCP; MCP server access is on request. CarbonTool says it is built and hosted in the EU, with emissions data kept on EU infrastructure under EU data protection law. These provisions may matter to organizations with integration or data-residency requirements.

Pricing

Starter is free for 30 days and requires no credit card. It covers core Scope 1 and 2 measurement, not Scope 3. There is no auto-charge, and trial data is retained for 90 days after access lapses, making it a bounded evaluation rather than an ongoing free tier.

All paid plans include full Scope 3 coverage across the 15 GHG Protocol categories. Core costs €2,000 per year for single-entity measurement and full platform access, with 2 hours of monthly support. It is the entry point for a single company that needs broader coverage but not multi-unit consolidation.

Pro costs €5,000 per year and adds multi-unit tracking and consolidation, VSME reporting, and 4 hours of monthly support. It is positioned for SMEs with multiple entities or a supply-chain focus; single-entity teams may not need its added organizational scope.

Enterprise costs €7,500 per year and includes multi-unit support, CSRD reporting, and 6 hours of monthly support with priority. It is aimed at large CSRD-obligated organizations that need those reporting and support provisions. The annual fees are substantial commitments, so the plan choice should reflect reporting scope and organizational complexity.

Platforms

CarbonTool is available on the web and through an API. Its data collection supports both manual and automated routes, including file imports and system connections.

Who it's for

CarbonTool is strongest for organizations building a structured emissions inventory, preparing framework-based reports or managing data across multiple units. Core fits a single-entity company seeking Scope 3 coverage; Pro better fits multi-entity SMEs; Enterprise is the clearest fit for large organizations with CSRD obligations. Starter is useful for a short Scope 1 and 2 assessment, but not for teams that need continuing free access or full-scope coverage.

Pros and cons

Pros: Broad data intake options and 200+ templates give teams multiple routes to build an inventory.
Pros: Source, unit, factor, quality level and audit trail attached to data points support traceability and review.
Pros: Separate entity tracking and group consolidation address organizational structures that a single inventory cannot represent as clearly.
Cons: Starter is limited to Scope 1 and 2 and lasts only 30 days, so it is not a durable free option for full emissions accounting.
Cons: Scope 3 requires a paid plan, starting at €2,000 per year, which may be more than a single-entity team needs if it only seeks a short-term assessment.

Alternatives

For a broader comparison, see Carbon Accounting Software.

Choose Greenio instead if a continuing free plan is more important: its free tier includes Scope 1, 2 and 3 tracking, unlimited data entry and four PDF reports per year.

Carbonfact offers a free supplier environmental-data exchange and LCA verification for teams focused on those tasks.

Consider CO2 AI if you want to try an enterprise platform free for 30 days and prefer pricing on request.

Persefoni has a free self-service plan for a single user, which may suit an individual rather than a multi-user team.

BigMile is another option for emissions accounting.

CarbonAnalytics may suit teams seeking a paid entry plan priced per business unit, with supplier, report-framework and user limits.

CarbonChain is another paid carbon-accounting option.

ACT Group Decarbonization Platform is another web-based option.

Verdict

Choose CarbonTool if your organization needs traceable emissions data, framework-based reporting and a path from measurement to reduction planning, particularly across multiple entities. Its main drawback is the cost of entry for full Scope 3 coverage, so teams that need only a free ongoing tier or supplier-specific tools should look elsewhere.

	CarbonTool	CO2 AI
Free plan	Yes	No
Free trial	Yes	Yes
Paid from	$166.67/mo	—
Open source	No	No
Platforms	api, Web	api, Web
Free plan	No	No
Scope coverage	scope 1-3	scope 1-3+
Data collection	both	both
Emissions factors	both	both
Supplier engagement	Yes	Yes
Audit trail	Yes	Yes
API access	Yes	Yes

CarbonTool vs CO2 AI

CarbonTool

CO2 AI