SB 253 reporting checklist
California's first SB 253 reporting cycle makes speed important, but auditability matters more than cosmetic completeness. The practical goal is a traceable inventory: each reported number should connect to a source, method, owner, review step and retained record.
Current timing
Last reviewed: 16 September 2026
As reviewed on 16 September 2026, CARB describes a proposed deferral of the first Scope 1 and Scope 2 reporting deadline from 10 August to 10 November 2026. Check CARB’s corporate greenhouse gas reporting program page and rulemaking status page for the approved deadline, filing instructions and first-year requirements before submission. Do not treat the proposed date as a confirmed final deadline, and do not assume you are already late based on an outdated date alone. GreenKPO supports data, evidence and reporting workflow — it does not provide legal deadline advice.
What we review
A readiness review tests whether your inventory can survive internal or external scrutiny — not whether a single spreadsheet looks complete.
- Entity boundary — reporting entity, consolidation method, inclusions and exclusions
- Source register — facilities, meters, fleet, process and fugitive sources reconciled to operations
- Scope 1 inventory — activity data, units, periods, owners and supporting evidence
- Scope 2 inventory — purchased energy by facility, missing months, estimation flags, factor method
- Emission factors — source, version, mapping and change control
- Evidence & approvals — evidence index, named approvers, locked files and review history
- Reviewer pack — ready responses for completeness, accuracy and methodology questions
Deliverables from a readiness review
- Gap register — missing sources, broken links and control weaknesses ranked by materiality
- Evidence request list — owner, due date and status for each open item
- Remediation backlog — prioritized fixes for the current cycle and for 2027 reuse
- Reporting readiness summary — what is reportable now vs what still blocks review
1. Confirm coverage and reporting boundary
- Approve the applicability decision for the reporting entity.
- Define the organizational boundary and consolidation method.
- List entities, facilities and operations included or excluded.
- Document the fiscal year represented by the emissions data.
2. Build the Scope 1 source inventory
- Stationary combustion: boilers, furnaces, generators and process heat.
- Mobile combustion: owned or controlled vehicles and equipment.
- Process emissions: relevant industrial or chemical processes.
- Fugitive emissions: refrigerants and other applicable leakage sources.
- For every source, retain activity data, units, period, owner and supporting evidence.
3. Build the Scope 2 energy inventory
- Map electricity, steam, heat and cooling purchases by facility.
- Identify missing months, estimates, landlord-controlled data and meter changes.
- Document emission-factor sources and the reporting method used.
- Keep contractual-instrument evidence where market-based reporting is used.
4. Control the calculations
- Completeness: Facility/source register reconciled to finance, property or operational records
- Accuracy: Unit conversions, formulas and factor mappings independently reviewed
- Consistency: Methodology changes identified, approved and explained
- Version control: Locked reporting file, change log and named approvers
- Traceability: Every material total links back to source data and assumptions
5. Prepare for review and assurance
Create an evidence index before reviewers ask for one. Assign each request to an owner, record open items and distinguish missing data from unresolved methodology decisions. Do not treat proposed timing changes or enforcement posture as permission to leave the process undocumented — confirm current CARB instructions before filing.
6. Assemble the preparation pack
Treat the list below as GreenKPO’s recommended preparation evidence for internal review — not as CARB’s exact filing requirements. Confirm the current filing instructions and required fields on CARB’s program and rulemaking pages before submission.
- Approved Scope 1 and Scope 2 totals for the applicable prior fiscal year.
- Methodology and organizational-boundary description.
- Emission-factor register and material assumptions.
- Evidence index and reviewer sign-offs.
- Submission owner, approved channel, deadline and proof of filing once CARB requirements are confirmed.
What happens after the readiness review
Gaps become a controlled workflow — not another one-off spreadsheet exercise.
SB 253 compliance workflow
Move from readiness gaps into a traceable Scope 1 and Scope 2 reporting process.
See SB 253 compliance software →Data collection & evidence
Structure missing source data, validation and the evidence chain behind each figure.
See data collection software →Typical source systems GreenKPO can structure
Utility and fuel bills, facilities and meter registers, fleet and travel exports, accounting activity files, emission-factor tables and supplier responses. GreenKPO helps ingest, validate and evidence these sources so teams prepare reporting — it does not replace legal counsel or assurance providers.
Run an SB 253 readiness review
Identify the evidence gaps most likely to slow internal or external review — then move into a controlled reporting workflow.