SB 253 reporting timeline and status as of September 20, 2026

Last reviewed: September 20, 2026

This is an independent summary, not legal advice. It reflects public sources we could read on September 20, 2026, and some CARB documents were not accessible to us. Every item is labeled so you can see whether it is confirmed, proposed, or not confirmed. Check CARB's program page and the court dockets for the latest.

Confirmed in CARB documents we read

February 26, 2026: The CARB Board approved the initial SB 253 and SB 261 regulation (Resolution 26-1) and directed staff to consider conforming changes with a 15-day comment period. The February version set the first Scope 1 and Scope 2 reporting date at August 10, 2026.
July 27, 2026: CARB issued a Notice of Public Availability of Modified Text, with comments due August 11, 2026. The modified text moves the first Scope 1 and Scope 2 reporting date from August 10, 2026 to November 10, 2026, moves the annual fee-determination notice date from September 10 to December 10, and clarifies that Scope 3 is not required for 2026.
2026 report scope: Only Scope 1 and Scope 2 emissions.
First-year approach: CARB has said it will use enforcement discretion for good-faith first-year submissions. CARB's March 2026 workshop slides state that third-party assurance is not required for the 2026 report.

Not confirmed

Whether the regulation is final. We found no CARB or Office of Administrative Law source showing final approval or an effective date. Law-firm alerts from August and September 2026 described the regulation as pending approval by the Office of Administrative Law. Treat November 10, 2026 as the date CARB has announced in its modified text, and check CARB before relying on it.
CARB's 2026 reporting guidance and intake platform. Law-firm alerts report that CARB posted guidance, a draft Scope 1 and Scope 2 template and a voluntary online intake platform in early September 2026. We could not open the guidance document ourselves.
A per-entity fee amount. We could not confirm one and do not state one.
Any adopted CARB rule on assurance-provider qualifications, accreditation or an approved-provider list.

Proposed only

These items appear in CARB staff presentations and are not adopted rules:

Scope 3 phase-in beginning with 2027: CARB's July 21, 2026 presentation described a phase-in limited to five categories (purchased goods and services, fuel- and energy-related activities, waste generated in operations, business travel and employee commuting), with the other categories voluntary. CARB staff described this as a preview of a future rulemaking.
Limited assurance of Scope 1 and Scope 2 beginning with 2027 reports. See the assurance guide.

Statutory dates

According to the statute (Health and Safety Code section 38532, as amended by SB 219), Scope 1 and Scope 2 reporting starts in 2026 on a date set by CARB, Scope 3 reporting starts in 2027 on a schedule set by CARB, and assurance requirements phase in through 2030. Confirm these on the official statute page.

Litigation

Chamber of Commerce v. CARB (C.D. Cal. No. 2:24-cv-00801) challenges SB 253 and SB 261. It is on appeal in the Ninth Circuit (No. 25-5327). On November 18, 2025, the Ninth Circuit granted an injunction pending appeal as to SB 261 only, and did not enjoin SB 253. CARB has said it is not enforcing SB 261 under that order. Secondary sources report oral argument on January 9, 2026. We found no merits decision as of September 20, 2026 and could not read the docket directly.
Exxon Mobil Corp. v. Sanchez (E.D. Cal. No. 2:25-cv-03104) was filed October 24, 2025 challenging SB 253 and SB 261. We could not confirm its outcome.

Court status can change quickly. Check the dockets directly.

Sources

SB 253 reporting timeline and status as of September 20, 2026

Last reviewed: September 20, 2026

Confirmed in CARB documents we read

February 26, 2026: The CARB Board approved the initial SB 253 and SB 261 regulation (Resolution 26-1) and directed staff to consider conforming changes with a 15-day comment period. The February version set the first Scope 1 and Scope 2 reporting date at August 10, 2026.
July 27, 2026: CARB issued a Notice of Public Availability of Modified Text, with comments due August 11, 2026. The modified text moves the first Scope 1 and Scope 2 reporting date from August 10, 2026 to November 10, 2026, moves the annual fee-determination notice date from September 10 to December 10, and clarifies that Scope 3 is not required for 2026.
2026 report scope: Only Scope 1 and Scope 2 emissions.
First-year approach: CARB has said it will use enforcement discretion for good-faith first-year submissions. CARB's March 2026 workshop slides state that third-party assurance is not required for the 2026 report.

Not confirmed

Whether the regulation is final. We found no CARB or Office of Administrative Law source showing final approval or an effective date. Law-firm alerts from August and September 2026 described the regulation as pending approval by the Office of Administrative Law. Treat November 10, 2026 as the date CARB has announced in its modified text, and check CARB before relying on it.
CARB's 2026 reporting guidance and intake platform. Law-firm alerts report that CARB posted guidance, a draft Scope 1 and Scope 2 template and a voluntary online intake platform in early September 2026. We could not open the guidance document ourselves.
A per-entity fee amount. We could not confirm one and do not state one.
Any adopted CARB rule on assurance-provider qualifications, accreditation or an approved-provider list.

Proposed only

These items appear in CARB staff presentations and are not adopted rules:

Scope 3 phase-in beginning with 2027: CARB's July 21, 2026 presentation described a phase-in limited to five categories (purchased goods and services, fuel- and energy-related activities, waste generated in operations, business travel and employee commuting), with the other categories voluntary. CARB staff described this as a preview of a future rulemaking.
Limited assurance of Scope 1 and Scope 2 beginning with 2027 reports. See the assurance guide.

Statutory dates

Litigation

Chamber of Commerce v. CARB (C.D. Cal. No. 2:24-cv-00801) challenges SB 253 and SB 261. It is on appeal in the Ninth Circuit (No. 25-5327). On November 18, 2025, the Ninth Circuit granted an injunction pending appeal as to SB 261 only, and did not enjoin SB 253. CARB has said it is not enforcing SB 261 under that order. Secondary sources report oral argument on January 9, 2026. We found no merits decision as of September 20, 2026 and could not read the docket directly.
Exxon Mobil Corp. v. Sanchez (E.D. Cal. No. 2:25-cv-03104) was filed October 24, 2025 challenging SB 253 and SB 261. We could not confirm its outcome.

Court status can change quickly. Check the dockets directly.