SB 253 reporting deadline November 10, 2026: what CARB's intake platform asks for and what to file

The short answer: on September 1, 2026 CARB published the material companies have been waiting for since July: a guidance document for the first reporting cycle, a voluntary online intake platform, an optional Scope 1 and Scope 2 reporting template, and an instructional video on the submission process. Reports are due November 10, 2026, they cover Scope 1 and Scope 2 only, and assurance is not required this year.

The part worth your attention is not the guidance. It is the intake platform, which asks for entity identification the written guidance never mentions, at a level of precision that will send a number of companies back to their tax filings. If you are running the first California filing for a group with subsidiaries, that is where the work is.

What CARB released on September 1, 2026

Four things, all voluntary in the sense that none of them is the legally mandated route. CARB has been clear that entities may still submit by emailing [email protected] directly, and that the template is optional. What the platform buys you is a standardized way to hand over the fee contact details, which matters more than it sounds like it should.

What the intake platform asks for that the guidance does not

Entity identity, drawn from your tax filings rather than from your sustainability reporting. The platform asks for the full legal name as filed on tax forms, a Federal EIN or California Corporation Number or Secretary of State file number, and the California Principal Business Activity code from the state tax filing. It also asks how many reporting entities the submission covers and whether fees should be paid combined or individually.

The rule that follows from this is worth stating plainly, because it catches groups that assumed the California filing would work like a consolidated financial statement: consolidated reporting is accepted, consolidated identification is not. A parent can file one emissions report covering the group, but every in-scope subsidiary still has to be named and identified individually. If your legal entity list, EINs and California business activity codes live with the tax function and your emissions data lives with sustainability, those two datasets have to meet before November 10, and in most companies they never have.

One more thing to plan around: uploaded emissions reports and statements of non-reporting will be made public. A statement explaining that you were not collecting data is a document your customers and competitors can read.

What you actually have to file by November 10

Less than most companies fear. The first cycle is Scope 1 and Scope 2 only. There is no Scope 3 requirement this year, the reporting template is not mandatory, and CARB has said it will accept submissions whether or not assurance has been obtained. You may submit an existing annual report or data you already prepared for another program.

The first-year discretion is narrower than the headlines suggest, and it is worth reading the condition precisely. Reported data is limited to what the entity possessed or was already collecting on or before December 5, 2024. An entity that was not collecting emissions data as of that date may submit a statement on company letterhead explaining that position rather than a report. That is a genuine accommodation, but it is a one-time one, and it is public.

• Scope 1 and Scope 2 only. Scope 3 is not in the first cycle.
• No assurance required. CARB accepts submissions with or without it this year.
• Template optional. An existing annual report or another program's data is acceptable.
• Data limited to December 5, 2024 posture. What you held or were collecting on or before that date.
• Non-collectors may file a letterhead statement instead of a report, and it becomes public.

The fee is assessed whether or not you file a report

This is the detail that turns a compliance question into a budget question. All covered entities are assessed the annual fee regardless of what they submit, including entities that file a statement of non-reporting. Under CARB's proposed structure, fee determinations are issued around December 10, 2026 and payment falls due within 60 calendar days.

Treat the fee amounts as proposed rather than settled. They sit inside a regulatory package that has not completed review, and the numbers CARB has published are its own estimates rather than a final schedule. We keep the current position, and what it means for a compliance budget, on SB 253 compliance cost.

Is the November 10 deadline actually final?

The date is firm as CARB's stated deadline, and it remains subject to approval of the regulation by the California Office of Administrative Law. As of early September 2026 that approval has not been granted. CARB approved the initial regulations on February 26, 2026, withdrew the package in June to make limited changes and move the deadline, released proposed modifications on July 27, and must run a 15 day comment period before resubmitting.

Two errors are circulating widely enough to be worth correcting. The first is that the initial report is due August 10, 2026. That was the original date in the withdrawn package and it is no longer operative; the date is November 10. The second is that the Ninth Circuit has ruled in the constitutional challenge. It heard argument in January 2026 and, as of this writing, has issued no decision. SB 261 remains enjoined and SB 253 does not, which is precisely why the November filing is going ahead. The threshold questions are covered on whether SB 253 applies below $1 billion.

What this means for the software you file with

For year one the emissions arithmetic is the easy half. Scope 1 and Scope 2 for most companies means stationary combustion, refrigerants, a vehicle fleet and purchased electricity, which is a bounded set of utility accounts, fuel cards and lease records rather than a supply chain. Teams that already capture fuel and utility spend as it comes in rather than reconstructing it from twelve months of PDFs in a shared mailbox will find the reporting half of this straightforward.

The harder half is the part CARB just made explicit. You need the emissions total attached to a specific legal entity, with the EIN and California business activity code beside it, and you need to be able to do that for every in-scope subsidiary. So the questions to put to a vendor are less about factor libraries than about structure:

• Can it hold emissions by legal entity, not just by site or business unit, and roll them up for a group filing?
• Can it carry entity identifiers such as an EIN alongside the emissions record?
• Can it produce both a Scope 1 and Scope 2 report and the underlying source documents, so a later assurance year is not a rebuild?
• Does every reported tonne trace back to an invoice, meter read or fuel record you can show?
• Does it handle the 2027 cycle, when assurance and the first Scope 3 categories arrive?

That last point is the one worth paying for. Year one is deliberately gentle, and building a filing that cannot survive the second year is a false economy. Our carbon accounting software starts from the invoices and ledger exports you already have, drafts a scope, category and emission factor for each line with a stated confidence, leaves the uncertain tail for a person, and keeps every reported tonne linked to its source document, which is what an assurance provider will ask for in 2027. The boundary and materiality decisions stay yours.

If you are choosing a platform for this specifically, start with SB 253 reporting software and the broader California climate disclosure software overview. If Scope 3 is already on your roadmap for the 2027 cycle, the method sequence is on Scope 3 emissions reporting requirements.

Dates, fee mechanics and platform fields on this page reflect CARB material published on September 1, 2026 and legal analysis of it as of September 5, 2026. The reporting deadline and the fee structure sit in a regulatory package that has not completed Office of Administrative Law review, so confirm the current position with CARB before you file. This is not legal or accounting advice.