Carbon accounting software for small business: what an SME actually needs

Usually less than it is sold: Scope 1 and 2 from fuel, refrigerant and electricity records, each calculated with the DESNZ factor set for the year the activity happened, and a way to answer customers’ supplier questionnaires from the same figures.

Most small businesses have no statutory carbon reporting duty, so start from what customers, tenders and lenders actually ask for, then decide whether a free tier, a spreadsheet or a paid platform carries it.

This site ranks no products and has tested none, so it names no best.

The useful question is which option passes the tests your own requests impose — factor year matched to activity year, Scope 1 and 2 with the evidence behind them, a Carbon Reduction Plan if you bid for an in-scope government contract, answers limited to the value-chain cap for an EU customer, and a full export — shown on your own data.

Yes, in the sense that some vendors publish a free tier or plan on their own pages: in this site’s registry, Measurabl, Persefoni, Small99, Worldfavor.

Each is described in the vendor’s own words on this page, usually with paid modules on top.

The DESNZ conversion factors are free to download from GOV.UK, and a spreadsheet using them can carry a first single-site Scope 1 and 2 inventory.

This site’s registry, built from vendors’ own sites, records no open-source carbon accounting platform, and this site has not surveyed code repositories, so it cannot say whether one would suit you.

Whatever the licence, the tests are the same: dated factors, a boundary, a change history and an export.

Almost certainly not.

SECR applies to quoted companies and to large unquoted companies and LLPs.

The exemption is framed as “not more than” qualifying conditions, so a company is large only when it exceeds at least two of £36 million turnover, £18 million balance sheet total and 250 employees, and after its first year that position has to hold for two consecutive years before its status changes.

A small business does not usually need SECR software, because SECR does not apply to it.

If a company is growing towards the thresholds, the SECR disclosure is short — UK energy use in kWh, the emissions from it, an intensity ratio, the methodology and the prior year — and any tool that keeps factor years and comparatives can produce it.

Only if you bid for a specific in-scope central government contract whose estimated value is above £5 million a year including VAT, averaged over the contract’s life, and the authority applies PPN 006. It is procurement policy, not a legal duty on companies.

The plan covers Scope 1 and 2 in full and five named Scope 3 categories, with a commitment to net zero by 2050.

CDP’s own FAQ says a discloser is exempt from the admin fee if it has only been requested to disclose by a Supply Chain member (or a Banks Program or Private Markets member, or RE100).

CDP has an SME questionnaire, scored for climate change only, and says its SME A score is not equivalent to the full corporate A score.

Answering is voluntary; any duty would come from your contract with the customer.

Where a customer reporting under the CSRD asks for information for that reporting, the value-chain cap stops it requiring more from a supplier with an average of no more than 1,000 employees in the preceding financial year than the datapoints in Annex II of the voluntary standard.

Above 10 employees those include estimated Scope 1 and location-based Scope 2; Scope 3 is not in Annex II.

The cap applies from financial years beginning on or after 1 January 2027, does not override a contract, and creates no obligation on the supplier to provide anything.

Most vendors do not publish a price.

Of the 13 vendors in this site’s registry that say they serve small or mid-sized businesses, 3 publish a figure on their own pages (Compare Your Footprint, Ecologi, Zevero) and 1 publish a free tier (Small99); the rest are recorded as Enterprise level · TBD.

Compare any quote against the hours your current process takes.

Often, for a first single-site Scope 1 and 2 inventory: activity data, the DESNZ factor set for the activity year, a written method and the bills behind each line.

It stops coping when a factor year must not overwrite the last, someone outside the team needs a change history, or Scope 3 rests on suppliers’ data.

For UK activity, the DESNZ government conversion factors for the year in which the activity happened: the 2026 set is for activity data falling entirely or mostly within 2026.

In that set UK electricity generated is 0.13096 kgCO2e per kWh and electricity consumed, including transmission and distribution losses, is 0.14396.

Usually the same thing as carbon accounting software for a small business: an organisation’s Scope 1, 2 and perhaps some Scope 3 emissions.

A product carbon footprint is a different boundary governed by product standards, and a customer asking for one is asking a different question from a customer asking for your company’s emissions.

No. This site has tested no products.

The page is built from the provisions of SECR, PPN 006, the GHG Protocol, the DESNZ factors, CDP’s own rules and the EU value-chain cap, each cited, and the vendor directory quotes only what each vendor publishes about itself.