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Regulatory Framework · California · Comparison

SB 253 vs. IFRS S2: the same data, different forms

A company preparing SB 253 disclosures and one preparing IFRS S2 are measuring almost the same emissions. Here is where the two line up, where the wording actually differs, and where one data set serves both.

Last updated:

Orientation only, current at the review date above. Not legal or accounting advice.

The short version
  • Both use Scope 1 / 2 / 3 definitions consistent with the GHG Protocol — the same underlying basis.
  • SB 253 is a California law with a CARB filing deadline. IFRS S2 is a global standard that binds a company only where a jurisdiction adopts it.
  • SB 253's first phase is Scope 1 + 2 only (Scope 3 later); IFRS S2 asks for Scope 1, 2 and 3 plus a governance and strategy narrative.
  • One dataset — activity data and a sourced emission factor — answers both; the wrapper around it differs.
  • Full explainers: California SB 253 & SB 261 and ISSB S2 / IFRS S2.

Two different things wearing similar names

SB 253 is a California statute: it has a filing deadline, a regulator (CARB) that enforces it, and it binds entities that meet its revenue and California-nexus thresholds directly. IFRS S2 is a standard issued by the ISSB — it becomes mandatory only where a jurisdiction chooses to adopt or build on it. A company can be in scope of one, both, or neither, and the two questions are answered completely independently of each other.

Data-point mapping

Data pointSB 253IFRS S2What a Passport carries
Scope 1 (direct emissions)Required, first reporting phaseRequired, part of Metrics & TargetsCalculated from fuel and vehicle activity data
Scope 2 (purchased energy)Required, first phase, location-basedRequired; location-based, market-based encouragedCalculated from electricity use and a sourced grid factor
Scope 3 (value chain)Required, later phase (previewed for 2027)Required, with relief provisions in early adoption yearsNot collected at category level; a Passport's Scope 1/2 can be one input to a customer's own Scope 3
Governance narrativeNot requiredRequired — one of four core pillarsNot collected — outside a Passport's scope
Strategy & climate-risk narrativeNot required (that is SB 261's territory, separately)Required — one of four core pillarsNot collected
Third-party assurancePhased in for later reporting years; not required for the first (2026) cycle — schedule set by a separate future CARB rulemakingNot mandated by the standard itself — depends on the adopting jurisdictionSelf-reported; not independently assured
Who has to reportEntities over ~$1B revenue doing business in CaliforniaOnly where a jurisdiction has adopted or mandated itSME suppliers usually report under neither — they answer a customer's request instead

Where they diverge

The clearest gap is narrative: IFRS S2 is built on four pillars — governance, strategy, risk management, and metrics & targets — and only the last of those is an emissions number. SB 253 doesn't ask for the other three at all; it is an emissions-disclosure law, not a climate-risk framework. Going the other way, SB 253 carries something IFRS S2 does not itself provide: a specific filing deadline and a state regulator that enforces it. IFRS S2's enforcement, if any, comes entirely from whichever jurisdiction adopts it.

If you only have to answer one

Build the Scope 1 and Scope 2 figures once, from real activity data and a sourced, named emission factor. That number is valid input to either framework's request. What changes is the wrapper: an SB-253-driven request usually wants the number and its calculation basis; an IFRS-S2-driven one wants the number sitting inside a broader governance-and-strategy narrative that a Passport does not produce. Know which one you're actually being asked for before assuming one answer covers both.

Common questions

Not usually. If you're an SME supplier, you are unlikely to file under either — you are answering a customer's request that is shaped by one or the other. The underlying activity data (fuel, electricity, vehicles) and the resulting Scope 1 and Scope 2 figures are the same regardless of which framework's language your customer used.

They ask for different things, which makes "stricter" the wrong frame. SB 253 is narrower but has the force of California law behind it — a filing deadline and CARB enforcement. IFRS S2 asks for more (governance and strategy narrative alongside the numbers) but is a standard that only binds a company where a jurisdiction has adopted it. Which one is more demanding for you depends entirely on which one your customer or regulator actually requires.

It covers the emissions numbers — Scope 1 and Scope 2 — but not the governance and strategy narrative that IFRS S2 also asks for. If a customer specifically needs IFRS S2-aligned climate-risk disclosure, your Scope 1 and Scope 2 figures are necessary but not sufficient; the narrative parts are a separate exercise your Passport doesn't produce.

A description of governance and strategy — who oversees climate matters, and how climate-related risks and opportunities affect the business financially. SB 253 is an emissions-disclosure law; it doesn't ask for that narrative at all. See our IFRS S2 guide for the full four-pillar structure.

A Passport calculates Scope 1 and Scope 2 from the same underlying activity data and sourced emission factor regardless of which framework a customer names, and carries both an SB 253-aligned and IFRS S2-aligned label where relevant. It is self-reported throughout and does not produce the governance/strategy narrative that IFRS S2 separately requires.

Reviewed on September 7, 2026. SB 253's assurance requirements for years after the first reporting cycle are set through a separate CARB rulemaking not yet finalised — treat that row of the table as directional, not a committed schedule. This page is orientation, not legal or accounting advice; confirm anything load-bearing against CARB, the IFRS Foundation, or a qualified adviser.

EcoDiligence ESG Passports are self-reported summaries structured for ESG disclosure workflows. Content is not independently assured. Information aligned with EFRAG VSME and IFRS S2 (ISSB) frameworks does not constitute formal compliance or certification.

One dataset, either wrapper

Generate Scope 1 and Scope 2 figures sourced and structured at a permanent link — free, ~10 minutes.