ISAE 3000 (Revised) — Not Withdrawn, Just Narrower
When ISAE 3410 was withdrawn, a great deal of commentary assumed its sibling went with it. It did not. ISAE 3000 (Revised) is in force, is not withdrawn, and no end date has been set for it.
What happens on 15 December 2026 is narrower and more precise: it stops being the standard for sustainability assurance, because ISSA 5000 takes that subject matter. Everything else it covers, it keeps.
If you buy assurance over anything other than financial statements and sustainability information — compliance with contract terms, non-sustainability performance indicators, systems and controls outside the service-organisation regime — this is still the standard your engagement runs under, and nothing about that changes.
1. It is not withdrawn
The IAASB’s staff FAQ says it in one sentence, and the sentence rewards careful reading:
The second “or” is doing the work. It excludes sustainability from the standard’s future scope; it does not end the standard. The sentence describes a narrowing, and narrowing is not withdrawal.
In March 2025 the IAASB approved the withdrawal of ISAE 3410, the greenhouse-gas-specific standard, with effect from 15 December 2026. No equivalent decision was taken about ISAE 3000 (Revised). If you read that both were withdrawn, the source has conflated a withdrawal with a change of scope.
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2. What it loses on 15 December 2026
One subject matter: sustainability information. From that date, an assurance engagement on sustainability information falls under ISSA 5000, and ISAE 3000 (Revised) is no longer the vehicle for it.
That is a real change for anyone who has been buying sustainability assurance under ISAE 3000 (Revised) — which, before ISAE 3410 and ISSA 5000, was the usual arrangement for everything that was not a greenhouse gas statement. Social metrics, governance disclosures, workforce data and the narrative parts of a sustainability report were commonly assured under it. All of that moves.
3. What it keeps
Everything else. The standard’s title states its scope by exclusion, and after December 2026 the exclusion list simply grows by one item.
| Subject matter | Standard after 15 December 2026 |
|---|---|
| Historical financial statements | The ISAs — an audit. Never ISAE 3000. |
| Review of historical financial information | The review standards. Never ISAE 3000. |
| Sustainability information | ISSA 5000 — the item that moves |
| Controls at a service organisation | ISAE 3402, the specific standard in the family |
| Pro forma financial information | ISAE 3420 |
| Anything else — compliance, non-sustainability KPIs, other non-financial subject matter | ISAE 3000 (Revised), unchanged |
The practical test is simple. Ask what the subject matter is. If it is neither historical financial information nor sustainability information, and no more specific standard in the family covers it, you are in ISAE 3000 (Revised) — on 14 December 2026 and on 16 December 2026 alike.
4. Attestation and direct engagements — the distinction that outlives the change
ISAE 3000 (Revised) provides for two shapes of assurance engagement, and the difference is about who does the measuring.
This matters for the transition because ISSA 5000 addresses attestation engagements, while ISAE 3000 (Revised) addresses both. For the overwhelming majority of sustainability work that is a distinction without a difference — an entity reports, a practitioner assures, and the engagement is an attestation engagement by construction.
It would be easy to read the two facts together and conclude that direct engagements on sustainability information have nowhere to go after December 2026. We are not saying that. What is on the record is what each standard addresses; the IAASB has not published a position on direct sustainability engagements, and neither should we. If your engagement is genuinely a direct one, raise it with your provider and your jurisdiction’s standard-setter rather than assuming either answer.
5. The route where it still covers sustainability
There is one circumstance in which ISAE 3000 (Revised) continues to be applied to sustainability assurance after December 2026, and it turns on adoption rather than on the standard itself.
It is the same shape as the route that keeps a jurisdiction-specific ISAE 3410 alive, and it has the same cost attached. The reason is stated plainly in the IAASB’s FAQ: ISAE 3000 (Revised) no longer applies internationally to sustainability assurance after that date, whatever a local adoption timetable says.
6. The ISAE family, and where 3000 sits in it
ISAE 3000 (Revised) is the umbrella standard. The numbered standards around it are specific applications, and knowing which one governs saves an argument at engagement acceptance.
| Standard | Subject matter | Status |
|---|---|---|
| ISAE 3000 (Revised) | The umbrella — assurance other than audits or reviews of historical financial information | In force |
| ISAE 3402 | Assurance reports on controls at a service organisation | In force |
| ISAE 3410 | Greenhouse gas statements | Withdrawn 15 Dec 2026 |
| ISAE 3420 | Pro forma financial information in a prospectus | In force |
| ISSA 5000 | All sustainability information — a new series, not an ISAE | Effective 15 Dec 2026 |
Note the numbering. ISSA 5000 is not ISAE 5000: the IAASB opened a new series for sustainability assurance rather than extending the ISAE family. That is a signal about how the Board sees the subject matter — not an application of assurance-other-than-audit, but a discipline of its own.
7. What an ISAE 3000 (Revised) engagement requires
The requirements will be familiar to anyone who has read ISSA 5000, and that is not a coincidence: the IAASB described its approach to the new standard as “no greenfielding”, building on established practice in ISAE 3000 and ISAE 3410 rather than starting over.
| Element | What it means |
|---|---|
| A three-party relationship | A practitioner, a responsible party, and intended users. If the intended users cannot be identified, the engagement has a problem before it starts. |
| An appropriate subject matter | Capable of consistent measurement or evaluation against the criteria. |
| Suitable criteria | The benchmark the subject matter is measured against, available to intended users. |
| Sufficient appropriate evidence | Enough, and of the right kind, to support the conclusion at the level engaged. |
| A written assurance report | In the form the standard prescribes, stating what was done and at what level. |
| Ethics and quality management | The IESBA Code and the firm’s quality management system, as for any assurance engagement. |
8. Limited and reasonable assurance
Both levels are available, and the distinction is the same one that carries into ISSA 5000: a reasonable assurance engagement produces an opinion in positive form; a limited assurance engagement produces a conclusion in negative form, on procedures that differ in nature and timing and are less in extent.
Because the two standards share this architecture, a reporter moving a sustainability engagement from ISAE 3000 (Revised) to ISSA 5000 is not changing the level of assurance they buy. They are changing the standard the practitioner works to.
9. What to check before December 2026
- Separate your engagements by subject matter. Sustainability work moves to ISSA 5000; everything else stays where it is. A single provider may be running both for you.
- Check what your sustainability engagement letter names. If it names ISAE 3000 (Revised) for a period beginning on or after 15 December 2026, it names a standard that no longer covers that subject matter.
- Leave your non-sustainability engagements alone. They are unaffected, and re-papering them on the assumption that ISAE 3000 is ending would be work done for no reason.
- Ask whether your jurisdiction has adopted ISSA 5000. If it has not, §5 applies — and so does the cost attached to it.
- Correct your own published references. A page describing ISAE 3000 (Revised) as the standard for sustainability assurance is accurate today and wrong in January.
10. How GreenCalculus implements this
The distinction this page draws is the one our diagnostics rest on: what an assurance standard puts on the practitioner, and what stays with you regardless of which standard applies.
- Assurance Readiness Checker — the assurer tests your inventory, boundary, controls and evidence. Naming and retaining the factors behind your numbers is your duty under every standard on this page.
- Emission Factor Vintage Checker — whether the factors behind an assured statement were current for the period they were applied to.
Factors in the MasterBrain carry their edition, publication and retrieval provenance, and historical values stay addressable by version. Changing the assurance standard changes who tests what; it does not change the fact that the evidence has to exist before the engagement asks for it.
11. Frequently Asked Questions
No. Only ISAE 3410, the greenhouse-gas-specific standard, was withdrawn — the IAASB approved that in March 2025 with effect from 15 December 2026. No equivalent decision has been taken about ISAE 3000 (Revised), and no end date has been set for it. What changes is its scope, not its existence.
One subject matter leaves. From that date ISAE 3000 (Revised) no longer applies to assurance engagements on sustainability information, which fall under ISSA 5000 instead. Every other engagement it covers — assurance that is neither an audit nor a review of historical financial information, and not about sustainability — continues under it unchanged.
Anything that is neither historical financial information nor sustainability information, and that no more specific standard in the family covers. Compliance with contractual or regulatory requirements, non-sustainability performance indicators, and other non-financial subject matter all remain within it. Controls at a service organisation go to ISAE 3402 and pro forma financial information to ISAE 3420, as they did before.
Yes, on one condition and at one cost. Where a jurisdiction has adopted ISAE 3000 (Revised) but not yet ISSA 5000, practitioners there may continue applying ISAE 3000 (Revised) until it does. But a practitioner who wants to claim compliance with IAASB standards for assurance on sustainability information cannot do so unless they apply ISSA 5000, because ISAE 3000 (Revised) no longer applies internationally to that subject matter after the effective date.
Who does the measuring. In an attestation engagement a party other than the practitioner measures the underlying subject matter against the criteria, and the practitioner reports a conclusion on the resulting information — management publishes, the practitioner assures. In a direct engagement the practitioner measures it themselves and presents the result with the assurance report. ISAE 3000 (Revised) provides for both; ISSA 5000 addresses attestation engagements.
Because the IAASB opened a new series for sustainability assurance rather than extending the ISAE family. That is a deliberate signal: sustainability assurance is treated as a discipline in its own right rather than as one application of assurance other than audits. Practically, it also means ISSA 5000 is stand-alone and does not require any other IAASB standard to be applied alongside it.
No. Both standards provide for limited and reasonable assurance, with the same conclusion forms — a positive-form opinion for reasonable assurance, a negative-form conclusion for limited. Moving a sustainability engagement from ISAE 3000 (Revised) to ISSA 5000 changes the standard the practitioner works to, not the level of assurance you are buying.
Only the sustainability ones, and only for periods beginning on or after 15 December 2026. A letter naming ISAE 3000 (Revised) for non-sustainability assurance is unaffected and should be left alone. This is the practical reason the distinction on this page matters: treating the change as a withdrawal produces a great deal of unnecessary work on engagements that never move.
Related References
- ISSA 5000 — the standard that takes sustainability assurance
- ISAE 3410 — the one that actually was withdrawn
- ISO 14064-3 — the ISO verification route, from a different standard-setter
- ISO 14064-1 — the inventory standard assurance is performed over
- CSRD / ESRS E1 — where assurance covers the whole sustainability statement
- Assurance Readiness Checker — what the assurer tests, and what stays yours
