Table of contents

The August deadline: strategic nuances of the final SB 253 rules

As we pass the mid-point of April 2026, the theoretical “wait and see” period for California’s climate disclosure laws has officially ended. Following the California Air Resources Board’s (CARB) decisive public hearing on February 26, the landscape for SB 253 has shifted from legislative debate to a hard-coded compliance reality.

While our previous guides cover the foundational “who, what, and when,” today’s update dives into the strategic legal nuances, informed by recent insights from Ropes & Gray, that every C-suite and sustainability lead must understand before the August 10 deadline.

FEBRUARY’S FINAL RULE

The “skinny” regulation and the August 10 SB 253 deadline

At the end of February, CARB finalized what legal analysts are calling a “skinny regulation.” At just seven pages, it doesn’t solve every complexity, but it does confirm the most critical detail: the first SB 253 reports for Scope 1 and 2 emissions are due on or before August 10, 2026.

Strategic insight: CARB explicitly rejected the idea of a “rolling deadline” based on a company’s fiscal year-end. This means whether your fiscal year ends in December or June, the August 10 finish line is fixed. If your fiscal year ended between January 1 and February 1, 2026, you are reporting on FY2026 data, but for everyone else, report on FY2025.

ENFORCEMENT DISCRETION

The “good faith” escape hatch (and its fine print)

CARB has reiterated that for this first 2026 reporting cycle, they will use enforcement discretion for “good faith” efforts. However, “good faith” is not a get-out-of-jail-free card.

To qualify under the CARB December 2024 Enforcement Notice, you must demonstrate:

  • Data retention: You must maintain raw emissions data and the underlying assumptions used for your calculations.
  • Transparency over limitations: If you have gaps in your data, you must disclose them rather than omitting the category entirely.
  • Progressive improvement: Documentation must show a clear path toward full compliance in 2027.

If your company was not collecting data as of December 5, 2024, you may be eligible for a first-year exemption. According to the CARB December 2024 Enforcement Notice, and confirmed in the February 2026 Initial Regulation, entities in this position must submit a formal statement on company letterhead to CARB explaining that they were not collecting data or planning to collect data at the time the notice was issued.

CORPORATE STRUCTURE

Parent-subsidiary mapping: beyond revenue

Under the amendments introduced in SB 219, reports can now be consolidated at the parent level — a significant relief for complex corporate structures that previously faced the prospect of thousands of individual subsidiary filings. However, the definition of “revenue” used to determine if you are in scope has been clarified in CARB’s regulatory guidance: it is strictly defined as global gross sales without deductions, meaning you cannot net out operating costs or business expenses to stay under the $1 billion threshold.

The pro-tip: Even if your parent entity plans to file a consolidated report, each individual subsidiary must still perform a “doing business in California” analysis. If a subsidiary meets the threshold independently, they are “in-scope.” The parent can file for them, but the mapping must be precise to avoid “incomplete filing” penalties (which can reach $500,000).

FINAL SPRINT

The 120-day action plan: preparing for the assurance era

With the August 10 deadline looming, the time for gap analysis is over; the time for data pressure-testing is here. While 2026 offers a “good faith” grace period, mandatory limited assurance for Scopes 1 and 2 begins in 2027. Treating this year as a “dry run” is the only way to ensure your emissions reporting can survive an independent audit next year.

  • 1
    Validate your “in-scope” mapping: Use the new CARB definitions for “parent,” “subsidiary,” and “revenue” to confirm exactly which entities are covered.
  • 2
    Pressure-test the voluntary template: CARB released a draft reporting template in October 2025. While use is voluntary for 2026, it is the best signal we have for what “good faith” looks like in CARB’s eyes.
  • 3
    Audit your “good faith” trail: If you are relying on enforcement discretion (or the data-collection exemption letter), ensure your documentation is rigorous. The “good faith” grace period only protects you if you can prove you tried.
  • 4
    Begin “pre-assurance” for 2027: Even if you aren’t filing a verified report this year, engage an assurance provider now to perform a “gap assessment.” Limited assurance in 2027 (and reasonable assurance by 2030) requires investor-grade data lineage that cannot be built overnight.
  • 5
    Standardize your Inventory Management Plan (IMP): To meet the 2027 assurance standards, your 2026 “good faith” efforts must be backed by a formal IMP that documents every data source, emission factor, and calculation methodology. This document will be the primary piece of evidence used by your third-party verifier.
Make it real

What to do next

If SB 253 landed in your inbox, the next 120 days are about sequencing, not scope expansion.

  • This week, confirm your “in-scope” mapping using the new CARB revenue definition and flag any subsidiaries that independently cross the threshold.
  • This month, decide whether you are filing a verified report or relying on good-faith enforcement discretion, and build the documentation trail accordingly — raw data, assumptions, gap disclosures, and a written improvement plan.
  • Before June, lock in an assurance provider to run a pre-assurance gap assessment, because a limited assurance opinion in 2027 cannot be retrofitted in 90 days.
  • Standardize your Inventory Management Plan now, even in rough form, so your August filing has the spine your 2027 verifier will actually ask for.

If any of these steps reveal a gap you can’t close internally, escalate to external counsel or a platform partner before July — not after.

Report with confidence

Contact Greenplaces today for a demo and discover how we can streamline your reporting journey.

Frequently asked questions

The first SB 253 reports for Scope 1 and 2 emissions are due on or before August 10, 2026. CARB’s February 2026 “skinny regulation” explicitly rejected a rolling deadline based on fiscal year-end, so the August 10 date is fixed regardless of when your fiscal year closes.

SB 253 applies to U.S.-formed entities doing business in California with global gross revenue over $1 billion. Revenue is defined as global gross sales without deductions — you cannot net out operating costs or business expenses to fall under the threshold. Parent entities can file consolidated reports, but each subsidiary must still run an independent “doing business in California” analysis.

CARB’s December 2024 Enforcement Notice defines good faith as a combination of three things: retaining raw emissions data and calculation assumptions, transparently disclosing data gaps rather than omitting categories, and documenting a clear improvement path toward full compliance in 2027. Good faith is not a waiver — it is a documentation standard.

Yes. SB 219 amended SB 253 to allow parent-level consolidated reporting, which is a meaningful relief for complex corporate structures. However, subsidiaries must still be mapped precisely; imprecise filings can trigger “incomplete filing” penalties of up to $500,000.

CARB can impose penalties of up to $500,000 per reporting year for non-filing or incomplete filing. Good-faith enforcement discretion is only available in the 2026 cycle and only if your documentation trail proves the effort.

Mandatory limited assurance for Scopes 1 and 2 begins in the 2027 reporting cycle, with reasonable assurance required by 2030. Because investor-grade data lineage cannot be built overnight, most compliance teams are using 2026 as a dry run — treating this year’s good-faith filing as the practice round for next year’s verified submission.

CARB’s regulatory guidance defines revenue as global gross sales without deductions. You cannot subtract operating costs, COGS, or business expenses to fall below the $1 billion threshold. If any individual subsidiary independently crosses the threshold, it is in scope — even if the parent plans to file on its behalf.

More resources from Greenplaces