Illinois HB 3673 (Proposed): Climate Corporate Accountability Act

Illinois HB 3673, the proposed Climate Corporate Accountability Act, would require large companies doing business in Illinois to publicly disclose their greenhouse gas emissions across Scopes 1, 2, and 3. The bill closely tracks California's SB 253, using the GHG Protocol Corporate Standard and Scope 3 Standard as its reporting basis and requiring independent third-party verification. It would be enforced by the Illinois Attorney General's office. As of introduction on February 14, 2025, it remains pending enactment.

The bill would apply to all public or private companies with global annual revenue over $1 billion on a consolidated basis that conduct business in Illinois, regardless of their state or country of incorporation.

Covered companies would be required to make annual public disclosures of their Scope 1, 2, and 3 greenhouse gas emissions, following the GHG Protocol Corporate Standard and Scope 3 Standard, with mandatory independent third-party verification of the reported data.

HB 3673 was introduced on February 14, 2025 and is currently pending enactment. If passed, the Illinois Secretary of State would finalize implementing rules by July 1, 2026.

The first Scope 1 and 2 reports would be due January 1, 2027 (covering FY 2026), with the first Scope 3 disclosure due within 180 days of the Scope 1 and 2 report, and annual reporting on the same cadence thereafter.