Trust

The ISO 14064-3 assurance path

Hemera prepares the evidence pack and an external assuror signs. The columns below show who does what.

Third-party assurance is an assuror's job. Hemera does not sign assurance opinions. It produces the evidence an assurance engagement needs. What an assuror asks for depends on the reporting context, so the split below varies by engagement.

Evidence Hemera produces

Methodology PDF
Section-by-section methodology bound to the publication snapshot.
Inputs hash
SHA-256 over the canonicalised input set. Anchors every replay.
Monte Carlo seed
Deterministic seed published with headline (5,000 iterations).
Override register
Every override, who recorded it, when, and the note they left.
Double-count guard results
Three checks across all 26 lines, results explicit.
Factor version lockfile
Pinned DEFRA factor versions for the reporting period.

Gates an assuror runs

Sampling plan
Risk-based sampling across emission lines and overrides.
Recalculation tests
Independent recompute of sampled lines vs published figures.
Override interview
Walkthrough of override decisions with the approver of record.
Materiality assessment
Aggregate error vs reporting materiality threshold.

Customer responsibility

Primary data quality
Survey design, response chasing, venue invoice provenance.
Override decisions
Sign-off on activity-to-factor mappings where ambiguous.
Attestation
Final figure attestation to the assuror at the close-out meeting.

What this demo doesn't claim

The Pawston Annual 2026 figure here is illustrative for the demo. It has not been through external assurance. The product ships the evidence pack; assurance, if you need it, is arranged by you with an accredited verifier of your choice.