What's the best carbon accounting software <em>for a small business</em>?
A big customer just sent you a supplier sustainability questionnaire. You don't have a sustainability manager, and you'd rather not sign a five-figure contract to fill it in.
The short answer: start with Persefoni Pro, which is free, to measure your footprint. If you need a formal report for several large customers, go with Greenly. If you sell into Europe and want a fixed price without a contract, Orki charges €1,440 excl. VAT with no commitment. Carbo fits French customers, Dcycle Spanish ones. Below: what each tool leaves out, what it really costs, and what to ask in the demo.
The ranking is editorial: a sponsored spot is always labeled on its card, and no affiliate link changes a score.
The right carbon tool for your business
Pro plan free with no time limit, paid export
Many big customersOne-click VSME report, export to EcoVadis, CDP and SBTi
No contract€1,440 excl. VAT, unlimited users, human support
French customersPublic price grid from €972 a year, Bilan Carbone® method
Spanish customersEU-hosted, ISO 27001
Free calculatorSelf-reported tool for small businesses
5 carbon accounting tools for small businesses, side by side
The "Commitment" column is the one most reviews skip. A 12-month subscription per entity, times three subsidiaries, costs a lot more than a plan you can cancel.
| Best for | Commitment | Free plan | Team size | Visit | ||||
|---|---|---|---|---|---|---|---|---|
| 1 | Persefoni | Free to measure | None | 4.1/5 | $0 | ✓ | Any size, 1 user | Visit → |
| 2 | Greenly | Many big customers | 12 months per entity | 4.3/5 | Quote | — | 50 to 250 employees | Visit → |
| 3 | Orki | No contract | No commitment | 4.1/5 | €1,440 excl. VAT | — | 20 to 250 employees | Visit → |
| 4 | Carbo | French customers | 12 months per entity | 4.2/5 | €972 a year | — | 10 to 100 employees | Visit → |
| 5 | Dcycle | Spanish customers | Quote | 3.8/5 | Quote | — | Companies selling in Spain | Visit → |
Prices from the vendors' official pages in 2026, in the currency each vendor shows. Carbo doesn't state whether VAT is included. "Quote" means no price is published.
Is your tool missing from this page? Email us: hello@hackceleration.com
How we picked tools that fit a small business
Most "best carbon accounting software" lists are written for enterprise sustainability teams, and many are affiliate pages. The top tools they recommend cost tens of thousands a year and expect a dedicated analyst. That's not you.
We compared each vendor's pricing and product pages, the free tools available to small companies, and feedback from users and practitioners. The rank follows what matters at 10 to 250 people: a price you can read, help from a human, and a report your customer will accept. That's why free Persefoni ranks above Greenly, whose overall score is higher but whose price is unknown. Each tool keeps the same scores across all our pages. Enterprise platforms like Watershed and Sweep are on our general ESG and carbon accounting ranking.
- Price clarity and commitmentA published price, per entity or not, with or without a 12-month lock-in.30%
- Human helpWithout a sustainability manager, a consistency check and real support beat another chart.25%
- Report you can hand overPDF, VSME, EcoVadis, CDP: the tool has to produce what your customer asks for.20%
- Method qualityGHG Protocol or Bilan Carbone®, activity data possible for scope 3.15%
- Time to completeGuided collection, number of users, invoice import: the hidden cost of a footprint.10%
No affiliate link changes a score or a rank.
Carbon tool pricing and customer reporting rules keep moving. Get the changes before your next supplier questionnaire
Persefoni
Persefoni is a US vendor, and its Pro plan is the only genuinely free carbon accounting tool in this ranking. No trial period, no time limit, no hidden fees. You get scopes 1, 2 and 3, with all 15 scope 3 categories, calculated on an annual basis, for one user.
Here's the catch for a small business. What your customer usually wants is a document, and exporting the emissions summary is a paid add-on. So are the GHG metrics reports (methodology, CDP, SECR), the breakdown by scope and category, the Net-Zero Navigator and Concierge support. Free to measure, paid to hand the result over.
Persefoni follows the GHG Protocol, the global standard most procurement teams ask about. That makes it a safe default for an English-speaking customer. If a French client insists on the Bilan Carbone® method, look at Carbo instead.
- Pro plan free with no time limit
- All 15 scope 3 categories
- GHG Protocol method
- ✓Zero cost to get your first footprint
- ✓No credit card, no contract
- ✓Handy for sanity-checking a consultant's number
- ✗One user only
- ✗Emissions summary export costs extra
- ✗Self-serve support on the free plan
- ✗Annual calculation only
Start here to find out where you stand. If your customer accepts a dashboard screenshot, you've paid nothing. If they want a formal report, price the export add-on before you build your year around it.
Greenly
Greenly is a French vendor, and it has the highest overall score in this ranking. For a small business, the most useful part is its VSME module: a one-click VSME report, data collection through an API (a direct connection to your other software), AI anomaly checks backed by human audits, and export to 15+ formats including EcoVadis, CDP and SBTi. If three customers send you three different questionnaires, that's the job it does well.
The downside is price visibility. No plan shows a price, there's no free trial, and the cost of a footprint depends on how complex your sector is. The only figure comes from Greenly's own guide: €2,000 to €10,000 for a small or mid-sized company. Users call it expensive for small teams, mention support that can be slow, and say the built-in reports are hard to customize.
One more thing: most published reviews come from companies with more than 50 people, often more than 200. Feedback from a 15-person business is thin.
- One-click VSME report
- Export to EcoVadis, CDP, SBTi and 12+ other formats
- API data collection plus human audits
- ✓One dataset for many customer questionnaires
- ✓Clear interface that walks you through the footprint
- ✓Grows with you if CSRD ever applies
- ✗No public price, no free trial
- ✗Seen as pricey by small teams
- ✗Few reviews from companies under 50 people
- ✗12-month commitment per entity
The right pick if your customers are large companies that change their questionnaire every year. In the demo, ask whether your scope 3 will be calculated from spend in euros or from activity data (tons, miles, kWh). The answer decides whether your reduction plan will ever show progress.
Orki
Orki is a French vendor that does two things almost nobody in this market does: it publishes a price, and it states plainly that its plans come with no commitment. The Compliance plan costs €1,440 excluding VAT. It covers what a customer or a regulator usually asks for: guided data collection, human support, all three scopes and the regulatory deliverables. Users are unlimited, which matters when finance, purchasing and logistics each have their own data to enter.
The two plans above it show two different prices on the same pricing page, depending on whether you read the card or the table. We don't quote them for that reason: get the number in writing. Life cycle assessment, CSRD and EcoVadis or VSME licenses are quote-only.
Orki is built for the French and European market and bills in euros. For a US company with no European customers, Persefoni or Greenly will feel more at home.
- Public price: €1,440 excl. VAT
- No commitment
- Unlimited users
- ✓A clear price your boss can approve in one email
- ✓Your whole team can enter data at no extra cost
- ✓Human support from the entry plan
- ✗Higher-plan prices are inconsistent on the page
- ✗VSME and EcoVadis licenses quote-only
- ✗Euro billing, French-market focus
The best balance of price clarity and hands-on help for a company that has to answer a European customer fast. If the request mentions VSME, ask for the VSME license price first: it isn't in the €1,440.
Carbo
Carbo is a French vendor and the only one here with a full public price grid for its carbon footprint product. All three plans are 12-month subscriptions per entity: Pro from €972 a year, Essentiel from €1,080, Premium from €1,404. The page doesn't say whether VAT is included, and the price changes with the company size you enter.
The plans differ in human help, not in the math. Pro already covers all three scopes with anomaly detection and dashboards, for one user. Essentiel adds three users, onboarding help, a consistency audit, a PDF report and live one-to-one assistance. Premium adds a dedicated carbon expert, a sector benchmark and SBTi targets.
Carbo uses the Bilan Carbone® method and appears on the ABC's public list of compliant tools, which a French customer may ask for. VSME reporting is a paid option on all three plans. Reviews are very positive, but there are only about twenty of them.
- Public price grid, €972 to €1,404 a year
- All three scopes from the Pro plan
- Bilan Carbone® method, VSME reporting as a paid option
- ✓You know the budget before you talk to anyone
- ✓Essentiel adds the audit and PDF report for €108 more than Pro
- ✓Multi-year and multi-entity discounts announced
- ✗Built for the French market
- ✗12-month commitment
- ✗VAT treatment not stated
- ✗Few public reviews
A strong pick only if France is part of your business. Otherwise, the Bilan Carbone® method buys you little, and Orki or Persefoni will be simpler.
Dcycle
Dcycle is a Spanish vendor that covers carbon accounting on all three scopes and CSRD preparation. It holds ISO 27001 (information security), says it is GDPR-compliant with EU hosting, and its plans page mentions no commitment. There's no public price: the plans page is a demo request.
The customers Dcycle names on its site are large industrial groups, so ask in the demo how it handles a company of your size.
- ISO 27001, EU hosting
- Three scopes plus CSRD preparation
- No commitment on its plans page
- ✓European vendor with security credentials
- ✓No-commitment wording on the plans page
- ✓Clear choice for Spanish supply chains
- ✗No public price
- ✗Reference customers are mostly large groups
- ✗Little feedback from very small companies
Worth a call if your customers are in Spain. For a US-only business, it brings little over Persefoni or Greenly.
What is your customer actually asking for?
Read the email or the questionnaire again before you book a single demo. Half the decision is there. A small business rarely has a legal duty to report; the customer's request sets the format, the scope and the deadline.
A supplier sustainability questionnaire
The most common case. Your emissions are part of your customer's scope 3, so they need your numbers. Check whether they want scopes 1 and 2 only, or all three. A free Persefoni Pro footprint can cover the first case.
An EcoVadis rating
Your footprint becomes evidence in your EcoVadis file. Pick a tool that exports to that format, like Greenly, or you'll retype everything by hand.
A CDP supplier request
Some buyers send their supplier requests through CDP. Greenly exports to CDP; Persefoni sells CDP reports as a paid add-on.
A European customer citing VSME
VSME is the voluntary standard the European Commission recommends for small companies. Below 1,000 employees, a customer can't demand more than VSME covers. Greenly has VSME reporting; Carbo sells it as a paid option and Orki sells a VSME license on quote.
Your bank or an investor
They usually want a baseline and a direction of travel. Ask for the format first, then decide whether a free measurement is enough.
A tender
When a tender asks for your emissions, a dated report on all three scopes is the safe answer: Orki Compliance or Greenly cover it.
- Does the request name VSME, EcoVadis, CDP or a custom form?
- Scopes 1 and 2 only, or scope 3 too?
- A signed report or a filled-in table?
- Which reporting year, and what deadline?
What carbon accounting really costs a small business
Only three vendors here publish a price. With those and the range Greenly gives for its own product, you can finally set a budget. Add your team's time: collecting purchase and travel data takes longer than the calculation.
Under 20 people, service business
Persefoni Pro at $0 for the footprint. Pay for the export add-on only if your customer wants a formal summary.
20 to 100 people, European customers
Orki Compliance at €1,440 excl. VAT with no commitment and unlimited users, or Carbo Essentiel from €1,080 a year if your customers are French.
100 to 250 people, several large customers
A Greenly quote, within the €2,000 to €10,000 range Greenly gives for a small or mid-sized company. Multiply by the number of entities if billing is per entity.
Very small and just curious
The SME Climate Hub's free calculator for small businesses gives a self-reported first number. Check its current sign-up terms first.
- Is the price per entity or per group?
- Is VAT or sales tax included?
- How many users are included?
- Is the report export included?
- Is there a multi-year discount?
What small businesses wish they'd known before signing
These come from vendor pages, user reviews and consultants who fix footprints that went wrong. They'll save you more than picking the right logo.
Ask whether scope 3 is spend-based
TrapSpend-based scope 3 gives you an order of magnitude. But it will never show the benefit of switching to a cleaner supplier at the same price. To show progress, you need activity data (tons, miles, kWh) for your biggest categories.
- Demo question
- Spend or activity data?
Test the export before you sign
TrapWhen you switch tools, you need to leave with your data, emission factors and results. Ask for a full export in the demo, not just a PDF. On Persefoni, even the summary export is a paid add-on: check that before you build your year on it.
- Must have
- Data, factors and results
Ask suppliers for data on day one
MethodFuel and energy bills take a day to collect. Scope 3 is often 80 to 90% of a small company's footprint and takes the longest, because it depends on your suppliers. Send your data request when you sign, not at the end.
- Scope 3 share
- 80 to 90% of the total
Use VSME as your shield
LeverageIf a European customer sends a 200-question survey and you have fewer than 1,000 employees, you can refuse ESG data requests that go beyond VSME. Answer the VSME scope well instead of everything badly.
- Threshold
- Under 1,000 employees
Avoid stacking 12-month contracts
BudgetGreenly and Carbo bill 12 months per entity. With three subsidiaries, that's three contracts. Orki states no commitment, and Carbo announces multi-year and multi-entity discounts: ask for both before you sign.
- Lever
- Multi-year or multi-entity
Ignore "certified" claims
CheckThe GHG Protocol doesn't certify software. When a vendor says "certified", ask who audited what. A compliant method doesn't make your data right either: a good tool fed bad numbers still gives a bad footprint.
- Ask for
- The audit document
Other options you'll come across, and why they're not ranked
A free calculator, vendors without a readable price, and platforms built for large groups. Any of them might work, but not as a small company's first pick.
SME Climate Hub calculator: free, self-reported
FreeA free, self-reported calculator for small businesses. Access has been tied to a net-zero commitment, so read the current sign-up terms.
- Price
- $0
- For
- Small businesses (SMEs)
Normative: Swedish, quote-only
QuoteNormative sells Essential and Premium plans, both on quote, with no free plan on its pricing page. Worth comparing only if you already have a Greenly quote in hand.
- Price
- Quote
Sami: software plus consulting
QuoteA French vendor partnered with the SGS group, selling a carbon hub, an ESG hub and consulting together, with a 6 to 12-month program to make your team self-sufficient. No public price. A good fit for a French mid-sized company, less so elsewhere.
- Price
- Quote
Watershed, Sweep, Tennaxia: built for large groups
EnterpriseThese platforms handle CSRD, double materiality and thousands of suppliers. For a small business answering one questionnaire, they're oversized and expensive. They're compared in our general ESG and carbon accounting ranking.
- For
- Large groups
Need more than carbon? Go here
These pages pick up where this one stops, for a small business that wants clean data before its footprint, or a larger company.
Watershed, Sweep, Tennaxia and other enterprise tools.
Your purchase invoices are everywhereBest accounting software for small businessClean purchase data makes scope 3 faster.
You want emissions next to your financialsBest financial dashboard softwareDashboards and KPIs in one place.
Carbon accounting for small businesses · FAQ
Is there free carbon accounting software for small businesses?
Yes. Persefoni Pro is free with no time limit and covers scopes 1, 2 and 3 for one user. The catch: exporting the emissions summary is a paid add-on. The SME Climate Hub also offers a free self-reported calculator for small businesses.How much does carbon accounting cost for a small business?
Anywhere from $0 (Persefoni Pro, measurement only) to around €1,000 to €1,500 a year for a published plan (Carbo from €972, Orki €1,440 excl. VAT). Greenly puts a small-business footprint at €2,000 to €10,000. The cost nobody lists is your team's time collecting invoices and supplier data.Do small businesses have to report their emissions?
In most cases, not by law. The EU's CSRD now targets companies with more than 1,000 employees and €450 million in revenue. In the UK, SECR applies to quoted companies and large unquoted companies; smaller ones report voluntarily. The real pressure comes from customers: your emissions are part of their scope 3, so they ask you for numbers.Can I just use a spreadsheet?
For a first pass on scopes 1 and 2 (fuel and energy bills), yes. Once you add scope 3, often 80 to 90% of a small company's footprint, a spreadsheet has no consistency checks and no history. That's when a $0 tool like Persefoni Pro or a €972 plan pays for itself in time saved.What is the VSME standard?
VSME is the voluntary sustainability reporting standard the European Commission recommends for unlisted small and mid-sized companies. If you sell to European customers, it's the format their questionnaires increasingly follow. A company with fewer than 1,000 employees can refuse ESG data requests that go beyond it.What's the difference between spend-based and activity-based scope 3?
Spend-based multiplies what you paid by an average factor per dollar or euro. It's fast but blind: switching to a cleaner supplier at the same price changes nothing. Activity-based uses tons, miles or kWh. Ask every vendor which one their entry plan uses.Do I need a consultant, or is software enough?
Software alone works for a service business with simple purchasing. A first footprint in manufacturing, or a reduction plan you'll have to defend, benefits from help. Plans with a built-in consistency audit, like Carbo Essentiel or Orki Compliance, sit in between.