SB 253, in plain language.
The Climate Corporate Data Accountability Act. It names only the largest companies doing business in California.
Its data requests reach everyone who sells to them.
Not sure what buyer questionnaire, Scope 1 or Scope 3 means? Definitions explains every term on this site, two lines each.
STATUS AS OF 2026-09-04 · show the sources
What it requires
US companies doing business in California with total annual revenue over one billion dollars. Below that line, the statute never names you.
Direct emissions and purchased energy, on 2025 data. Deferred from August 10 to November 10, 2026.
No standard template and no outside check required in year one.
Everything in the chain — suppliers, transport, product use — due within 180 days of each Scope 1·2 report.
This is the clause that leaves the building.
Third-party assurance moves from limited to reasonable for Scopes 1·2; limited assurance arrives for Scope 3, subject to board review.
The Ninth Circuit declined to block SB 253 in November 2025 — the same ruling that stayed SB 261.
Detailed rules adopted February 2026.
How it reaches companies it never names
A company filing this cannot work out Scope 3 from its own books.
- The number lives in its supply chain
- So the law reaches smaller companies as a request from their largest customer — a form with a deadline, not a rule with a threshold
- Where no supplier number exists, they estimate from industry averages
- And an average knows nothing about what your operation actually does
The sources
- SB-253 bill text — California Legislative Information · 2023-10-07
- CARB defers initial SB 253 reporting deadline — Proskauer Rose · 2026-06-26
- CARB adopts initial SB 253/261 regulations — Miller Nash · 2026-03-30
- Ninth Circuit enjoins SB 261, declines to enjoin SB 253 — Jones Day · 2025-11
- Why SB 253 reshapes supplier relationships — UL Solutions