Almost every vendor here sells a greenhouse gas inventory, yet hardly one prints what it costs.
This guide ranks thirteen on what the first year involves: whether any price is visible, how long the contract runs, who supplies the emission factors, what you can export afterwards, and whether the product still belongs to the company that built it.
Vendors can pay for more visibility on this website, for example a higher place in a ranking or more room on a page. Commercial relationships can also affect which products we feature and how prominently. Every vendor link is marked the same, whatever the arrangement behind it. How that works.
In short
What carbon accounting software does
Carbon accounting software turns activity and spend data into a greenhouse gas inventory across Scope 1, 2 and 3, using emission factors, and produces the figures needed for disclosure frameworks.
The ranking follows five checks. Setup effort comes first, then real cost, then the route for getting data out, then lock-in, then the intended buyer. One rule overrides the order: smaller vendors take the first three places when the category offers them, and the best-known brands start at four. Why those five, and why there is no score out of ten, is on the how we work page.
Scope 1 and 2 entry tier with a printed annual price
Ranked #1 of 13 in Best Carbon Accounting Software in 2026.
Published pricingElsewhere
Zevero is the cheapest way here to find out what a first inventory costs, because the Lite tier has a printed yearly price and larger plans are quoted. Users are unlimited on every plan and onboarding is included, which removes two usual line items.
Data leaves as Excel or CSV. The factor set draws on DEFRA, ecoinvent and EPA among seven databases. The catch is commitment: a year minimum and quarterly reviews, with no trial.
What stands out
Unlimited users
Annual contract
Spreadsheet export
Where it costs you
Entry tier handles only Scope 1 and 2, so Scope 3 needs a larger plan.
Every plan carries a one-year minimum term and no self-serve trial exists.
Right for
Small firms wanting a Scope 1 and 2 inventory at a known annual price
Wrong for
Buyers who want to test with their own data first
Not stated by the vendorEntry tier published per year; three larger plans quoted
Modular footprint accounting sold in four sizes, with CBAM and EUDR add-ons
Ranked #2 of 13 in Best Carbon Accounting Software in 2026.
Pricing on requestEurope
Carbmee splits its offer into Small, Medium, Large and Enterprise by module set and service level, not by seats. Small has core accounting, supply chain, product footprints, its own database and CSRD; Medium adds Studio; the bigger plans add forecasting, CBAM, EUDR, API and analytics as listed.
Enterprise includes strategic implementation and supplier engagement. Because everything is quoted and no trial is mentioned, the module list is the thing to negotiate before the price.
What stands out
Product footprints
Module-based plans
CBAM and EUDR
Where it costs you
The pricing page shows no currency, billing basis or user limit.
CBAM, EUDR and API access depend on which plan you take.
Right for
Manufacturers needing product footprints with CBAM or EUDR modules alongside
Wrong for
Teams wanting a self-serve start or visible prices
Berlin platform that logs emissions, models cuts and drafts disclosures
Ranked #3 of 13 in Best Carbon Accounting Software in 2026.
Pricing on requestEurope
Cozero organises work as Log, Act and Share. Log consolidates Scope 1, 2 and 3 across entities and sites; Act models reduction scenarios by return on investment and payback; Share prepares audit-ready CSRD and CDP disclosures.
API access and supplier engagement for Scope 3 data are on the list too. It is a Berlin GmbH founded in 2020. The only way to get a number is a demo request.
What stands out
Reduction scenarios
Supplier engagement
API access
Where it costs you
No pricing appears anywhere on the site; its pricing address returned a 404.
No owner or parent company is stated, so independence cannot be confirmed.
Right for
Mid-sized companies wanting reduction scenarios next to their inventory
Product-level life cycle assessment priced by catalogue size
Ranked #4 of 13 in Best Carbon Accounting Software in 2026.
Pricing on requestElsewhere
Ecochain tiers by catalogue: Professional is one user and fewer than 20 products with monthly billing, Business is multiple users under 200 products, and Enterprise goes beyond that.
The FAQ says price follows product count, data and IT complexity, supply chain complexity, add-ons and term. The trial lasts seven days, mirrors the paid features, and includes two half-hour expert calls. No plan shows a number, and the country is not stated.
What stands out
Product LCA
Trial with expert calls
Catalogue-based tiers
Where it costs you
The trial is capped at ten Ecoinvent datasets.
Business and Enterprise plans bill annually only.
Right for
Producers who need life cycle results for individual products
Wrong for
Companies that only need a corporate Scope 1-3 inventory
Not stated by the vendorQuoted per plan, tiered by product count; 7-day trial
Footprints for every product a manufacturer sells, with unlimited seats
Ranked #5 of 13 in Best Carbon Accounting Software in 2026.
Pricing on requestElsewhere
Carbonfact lists Carbon Accounting for the company inventory and Product LCA across the whole catalogue, both with unlimited users, plus Reporting, Decarbonisation and Expert Services.
Prices sit behind request buttons and depend on product count, data and IT complexity, supply chain complexity, add-ons and term. The homepage claims audit-ready output for more than ten frameworks and over fifty integrations. No trial is offered.
What stands out
Product LCA
Unlimited users
50+ integrations
Where it costs you
Reporting and decarbonisation are separate paid add-ons.
No country, address or registration appears on the pages read.
Right for
Product companies assessing every item they sell, with many users
Wrong for
Buyers wanting a trial or any published price
Not stated by the vendorQuoted per offering; no trial offered
Company and product footprints plus supplier engagement from Singapore
Ranked #6 of 13 in Best Carbon Accounting Software in 2026.
Pricing on requestAsia-Pacific
Terrascope lists five platform modules: Corporate Carbon Footprint, Product Carbon Footprint, Supplier Engagement, Climate Reporting, and Energy, Waste and Water. It adds AI Scope and Land Emissions and Removals offerings.
No plans, currencies or caps are listed, and the sole action offered is Book demo. A Singapore address is shown. No integrations or owner are named, so ask for both.
What stands out
Supplier engagement
Product footprint
Demo only
Where it costs you
Its pricing page names no plans, caps or connectors.
No trial is offered; the only action is booking a demo.
Right for
Corporates wanting company, product and supplier footprints from one vendor
Wrong for
Anyone comparing plans before speaking to a salesperson
Three named GHG tiers aimed at small and mid-sized firms
Ranked #7 of 13 in Best Carbon Accounting Software in 2026.
Pricing on requestEurope
Greenly's GHG plan has three tiers: GHG Report Compliance, Climate Action Ready and Net Zero Contributor, separated by how deep the measuring goes, what reduction help is included and how much support you get.
It covers TCFD, SBTi, CBAM and EUDR, and sells life cycle analysis and ESG as other plans. Its Paris founding dates to 2019. After the announced merger with Normative, confirm which product and contract apply to you.
What stands out
Tiered GHG plans
TCFD and SBTi
Merger with Normative
Where it costs you
No tier carries a numeric price.
Life cycle analysis and ESG are separate plans on top of the GHG tiers.
Right for
Small and mid-sized firms wanting named tiers and compliance help
Wrong for
Buyers needing certainty about the post-merger product line
FranceQuoted on request; separate LCA and ESG plans
Berlin tool pairing a certified method with AI decarbonisation modelling
Ranked #8 of 13 in Best Carbon Accounting Software in 2026.
Pricing on requestEurope
Plan A combines Scope 1-3 accounting with disclosure reporting and AI-assisted decarbonisation modelling. Its method is GHG Protocol compliant and certified by TUV Rheinland, and the company says it is B Corp and SOC 2 compliant.
The site names clients such as BMW, Visa and Mollie. Berlin is the base, with a Paris office, and the company dates to 2017. Everything about price happens in a sales conversation.
What stands out
TUV-certified method
SOC 2
Reduction modelling
Where it costs you
Prices are quoted on request with no plan list published.
Venture funding means the company is not independent of investors.
Right for
Companies wanting an audited method and a reduction plan
Paris platform folding carbon and wider ESG data across the value chain
Ranked #9 of 13 in Best Carbon Accounting Software in 2026.
Published pricingEurope
Sweep covers measurement, reporting and reduction of Scope 1-3 emissions and wider ESG data along the supply chain.
It is B Corp certified and registered as an Entreprise a Mission, and it counts membership of the Carbon Pricing Leadership Coalition, France Invest and IETA. Paris is where it began, in 2020, with London and a Denver office added. Cost is only discussed after a demo.
What stands out
Scope 1-3
ESG data
Entreprise a Mission
Where it costs you
No price, plan list or trial is published.
Breadth across ESG data may exceed what a carbon-only buyer needs.
Right for
Larger groups wanting carbon and wider ESG data in one system
Wrong for
Small firms needing a short, budgetable carbon-only start
Two-plan carbon product whose maker now sells sovereign AI systems
Ranked #10 of 13 in Best Carbon Accounting Software in 2026.
Pricing on requestElsewhere
Net0's pricing page has two plans. Platform has Scope 1 and 2, spend-based Scope 3, over 100,000 emission factors and reporting tools for CSRD, ESRS and CDP.
Enterprise adds more than 60 apps, unlimited custom integrations, activity-based Scope 3 in all 15 categories, API access and managed vendor outreach. Both are sold through its team; no trial is mentioned. The site says built in the UAE.
What stands out
Spend-based Scope 3
CDP and CSRD tools
Two plans
Where it costs you
Integration on Platform is limited to select Net0 Apps.
The homepage now centres on custom AI systems for governments.
Right for
Firms starting with spend-based Scope 3 and planning an upgrade
Wrong for
Buyers who need a stated legal seat or visible prices
Not stated by the vendorTwo plans, both quoted; no trial mentioned
Supply-chain footprint software now owned by Green Project Technologies
Ranked #11 of 13 in Best Carbon Accounting Software in 2026.
Pricing on requestElsewhere
The Emitwise site says Green Project Technologies acquired the software in July 2025 and that it now powers the owner's supply-chain and product footprint capabilities. Demo requests go to the Green Project website.
The pages read show privacy, cookie and terms links but no imprint, so the legal entity and country are unstated. Treat it as a product in transition and ask who contracts, supports and hosts it.
What stands out
Supply chain
Acquired 2025
Demo route
Where it costs you
The software now belongs to Green Project Technologies.
The site shows no pricing, trial, limits or country.
Right for
Existing users following the product under its new owner
Wrong for
New buyers who want a stand-alone vendor with clear terms
Not stated by the vendorNothing shown; demos routed to the new owner
Climate accounting for companies and financial institutions, with a no-limit starter
Ranked #12 of 13 in Best Carbon Accounting Software in 2026.
Free tierPublished pricingNorth America
Persefoni offers Persefoni Pro as a plan with no time limit, covering Scope 1-3 footprints and a sustainability report builder. The Advanced plan is quoted.
Add-on GHG metrics reports and services for California SB 253 and SB 261 are priced on top. It serves financial institutions as well as companies, and is based in Arizona. Start on Pro, then price what your disclosure regime adds.
What stands out
Starter plan
Financial institutions
Add-on reports
Where it costs you
Framework-specific GHG reports are paid add-ons to the starter plan.
California reporting services are priced separately by the vendor.
Right for
Companies and lenders wanting to try Scope 1-3 on real data
Wrong for
Buyers wanting one all-in price covering reports
United StatesFree plan with no time limit; Advanced quoted
Enterprise emissions platform with a removals and clean power marketplace
Ranked #13 of 13 in Best Carbon Accounting Software in 2026.
Pricing on requestNorth America
Watershed combines an AI-assisted platform, a library the vendor puts at 2.3 million emission factors and a marketplace for carbon removal, clean power and sustainable aviation fuel.
San Francisco is the base, with offices in several other cities. A Series C raised in February 2024 funds it. Cost is not on the site, so shortlisting by price means asking for a quote.
What stands out
Enterprise scale
Factor library
Offset marketplace
Where it costs you
The vendor publishes no pricing anywhere on its site.
Built around enterprise sustainability teams rather than small ones.
Right for
Large corporates with a sustainability team and complex supply chains
Wrong for
Small companies needing a fast, cheap first inventory
United StatesNot published; sold to enterprises by contract
Carbon accounting software turns activity and spend data into a greenhouse gas inventory across Scope 1, 2 and 3, using emission factors, and produces the figures needed for disclosure frameworks. A feature table will not settle this choice. These steps will.
01
Start with pricing transparency
Prices are public at 3 products (Zevero, Sweep, Persefoni) and on request at the remaining 10, so budget time for quotes if your favourite is in that second group.
02
Ask which country the contract runs through
Jurisdiction is a buying criterion here. The 13 vendors are spread over 5 countries (Europe 5, Elsewhere 5, North America 2, Asia-Pacific 1), and the home country determines which disclosure rules bind them.
Why carbon accounting software prices stay hidden
Of the thirteen products here, only Zevero prints any figure, and that is just its Scope 1 and 2 entry tier. Carbmee, Cozero, Terrascope, Sweep and Watershed route you to a demo, and Terrascope shows a single booking button. That is a problem because the invoice depends on things you cannot see from outside: product count at Ecochain and Carbonfact, module set at Carbmee, tier depth at Greenly.
Ask each vendor for a written quote naming users, entities, products and modules, and ask what the second year costs. Compare quotes only when they cover the same scope. A cheap Scope 1 and 2 price tells you nothing about the cost of adding supplier data later.
Quote names users, entities, products and modules
Second-year price stated in writing
Scope 3 cost shown separately from Scope 1 and 2
Company inventory or product footprint
These are two different products wearing one label. A company inventory sums emissions across Scope 1, 2 and 3 for reporting under a framework. A product footprint, a life cycle assessment, measures one item, and its price follows how many items you assess.
Ecochain tiers by catalogue size, Carbonfact sells company accounting and Product LCA as separate offerings, and Greenly sells life cycle analysis as its own plan. Zevero Lite, by contrast, stops at Scope 1 and 2. Decide which one your customers or regulators are asking for before looking at demos, because buying the wrong type means paying twice. Check the trial too: Ecochain caps its trial at ten Ecoinvent datasets.
Decide inventory, product footprint or both
Count products you must assess
Trial data limits noted before testing
Contract length and ownership in carbon accounting
Several vendors on this page have changed hands or direction. Greenly and Normative announced a merger in September 2026, Green Project Technologies acquired Emitwise in July 2025, and Net0 now describes itself as a builder of AI systems for governments. Add Zevero's one-year minimum on every plan and a pattern appears: you can be locked into a product whose owner or focus moves on.
Ask who the contracting company is, who hosts the data, and what happens to your contract if the vendor is acquired. A published exit route matters more here than in most software categories because disclosure history has to stay comparable between reporting years.
Contracting entity named in the order form
Change-of-control clause read
Ownership checked on the vendor site this month
Exporting your emissions data from Persefoni, Watershed and others
A footprint is a multi-year record, and auditors will ask how last year's figure was built. Zevero says data exports as Excel and CSV; the material we hold for Persefoni, Watershed, Plan A and Sweep names no export route, so ask for it in writing.
Request the activity data, the emission factors used with their versions, and the calculation method, not just the final tonnage. Persefoni's no-limit starter plan is a cheap way to test whether your own data loads and leaves cleanly. Carbmee and Net0 gate API access to higher plans, which affects how easily you can pull data into your own tools later.
Export format for raw activity data confirmed
Emission factor versions included in export
API access plan identified before signing
What goes wrong most often when buying carbon accounting software
Buying a company inventory when customers actually ask for per-product footprints, or the reverse.
Comparing a quote for Scope 1 and 2 with one that includes supplier engagement and Scope 3.
Taking a vendor's analyst placements as evidence it fits a company of your size.
Signing a multi-year term with a vendor that has recently been acquired or merged.
07
Frequently asked questions
6 answers
What is the best carbon accounting software in 2026?
Our ranking of 13 puts Zevero first. The only vendor on this page that prints a number: the Lite tier covers Scope 1 and 2 for a stated yearly figure, so a small company can budget before talking to anyone.
Every plan includes unlimited users and onboarding. Against that, every contract has a one-year minimum, there is no self-serve trial, Lite stops short of Scope 3, and the page names no direct integrations.
Which carbon accounting tools publish their pricing?
3 out of 13 state a price model on their own site:
Zevero: Entry tier published per year; three larger plans quoted.
Sweep: Quoted after a demo; nothing published.
Persefoni: Free plan with no time limit; Advanced quoted.
Everything else on the list is priced on request.
Is there a free carbon accounting tool?
Persefoni come with a no-cost entry point, a free plan or a self-hosted edition.
Where are these carbon accounting software vendors established?
The headquarters are spread over 5 countries and 4 regions, Europe 5, Elsewhere 5, North America 2, Asia-Pacific 1:
Zevero: Not stated by the vendor.
Carbmee: Germany.
Cozero: Germany.
Ecochain: Not stated by the vendor.
Carbonfact: Not stated by the vendor.
Terrascope: Singapore.
Greenly: France.
Plan A: Germany.
Sweep: France.
Net0: Not stated by the vendor.
Emitwise: Not stated by the vendor.
Persefoni: United States.
Watershed: United States.
What should you use instead of Zevero?
The next in line are Carbmee, aimed at Manufacturers needing product footprints with CBAM or EUDR modules alongside, and Cozero, aimed at Mid-sized companies wanting reduction scenarios next to their inventory.
Who should not buy Zevero?
Buyers who want to test with their own data first. Entry tier handles only Scope 1 and 2, so Scope 3 needs a larger plan..
If a carbon accounting software product of yours deserves a place among these 13, say what it is and who it serves. Inclusion rests with us alone. See software advice for the rules.
