Test the ledger,
not the PDF.
cobank gives assurance teams read access to a client's sealed reporting periods — every line item, the factor version it was calculated against, the full edit history, and the period's snapshot hash. You sample, test, and record conclusions in the same system that produced the number. Auditor access is free on every plan.
Evidence you can re-perform
Most sustainability reports arrive as a PDF with a spreadsheet behind it, and the spreadsheet has a version history nobody can produce. cobank keeps the population itself testable: each reported kilogram of CO₂e traces to an invoice line, the line to an emission factor version with effective dates and a source citation, and every edit to an append-only SHA-256 chain. Recalculate any line and you get the same number the client reported — or a difference you can point at.
How an engagement runs
Your client closes a period
Lines freeze, the snapshot hash is computed, and the period becomes the fixed population your procedures run against.
Your firm is invited
The client grants your engagement team read access to the closed period. No licence fee — auditor and reviewer access is free on every cobank plan.
Sample, test, record
You work in a separate auditor surface: draw samples, open the underlying invoice image next to the calculated line, and record each assertion as pass, exception, flagged, or not applicable — with your notes attached as workpapers.
Export the audit package
Workpapers, samples, conclusions, and the hashes needed for re-performance leave the system as one package for your firm's own files.
Standards you work against
The evidence model is built for limited and reasonable assurance under ISSA 5000 and ISAE 3410, with ISA 320 / ISA 530-style materiality and sampling in the workbench. Calculations follow the GHG Protocol Corporate Standard; report exports carry the period's snapshot hash so the figures you signed are the figures that stay on file.
The full calculation methodology — factor selection hierarchy, unit conversions, correction rules, and what happens when a line has no confident match — is public on the methodology page. It is written to be tested against, not marketed with.
"The auditor is not an afterthought here. The auditor is the second user the system was designed for." Frédéric Beckmann · Founder, cobank.ai
Calibrate against a real ledger.
Thirty minutes, a sealed demo period on screen, your engagement checklist against it. No slides.