Materiality — Definition and GHG Accounting Context
No company can report everything. A sustainability report that tried to would be unreadable, and a report that includes the wrong things is as misleading as one that leaves the right things out. So every reporting framework needs a rule for deciding what belongs in the report and what does not — and that rule has a single name.
The rule is materiality. Materiality is the principle that decides which information is significant enough to disclose — and in sustainability reporting it comes in two directions, financial and impact, whose combination is the much-discussed “double materiality”.
Materiality is the threshold that determines which information is significant enough to be disclosed: an item is material if omitting or misstating it could influence the decisions of the people who rely on the report. In sustainability reporting it has two directions — financial materiality (how issues affect the company’s value) and impact materiality (how the company affects people and the planet). Combining both is double materiality, the basis of the EU’s CSRD; the ISSB uses financial materiality alone, GRI uses impact.
What Materiality Means
The idea of materiality comes from financial accounting and auditing, where information is judged material if omitting, misstating or obscuring it could reasonably be expected to influence the decisions that users make on the basis of the accounts. It is, in essence, a threshold of significance: a filter that separates what must be reported from what can be left out because it would not change anyone’s decision. Materiality is why financial statements do not list every paperclip — the paperclips are immaterial.
Information is material if omitting, misstating or obscuring it could reasonably be expected to influence the decisions that users of a report make. Materiality is the threshold that decides what goes into a report — nothing more exotic than that. Everything else about materiality is a question of whose decisions, and about what, you are testing against.
Sustainability reporting borrowed this concept and gave it a much wider job. The “users” are no longer only investors reading financial accounts; depending on the framework they may also include employees, communities, regulators and civil society. And the subject matter is no longer only money but a company’s environmental and social performance — its emissions, its water use, its labour practices. Materiality is what turns that vast possible territory into a defined report: it decides which sustainability topics a company must address and which it may set aside.
The Two Directions: Financial and Impact
The single most important thing to understand about materiality in sustainability is that it can be assessed in two opposite directions, depending on whose interests you are protecting and what you are testing for.
Outside-in — financial
How do sustainability issues affect the company? Climate change, resource scarcity or regulation can hit cash flows, costs and enterprise value. This “outside-in” view protects investors and is the basis of financial materiality.
Inside-out — impact
How does the company affect the world? Its emissions, pollution and labour practices have effects on people and the environment, judged by their severity rather than their price tag. This “inside-out” view is impact materiality.
These are genuinely different tests, and a topic can be material under one and not the other. A company’s greenhouse-gas emissions may be highly material as an impact (they harm the climate) long before they are financially material to the company itself; a looming carbon tax may be financially material well before the company’s own footprint is large. Keeping the two directions straight is the key to the whole subject — almost every confusion about materiality is really a confusion about which direction is being tested.
Financial, Impact and Double Materiality
From those two directions come the three “flavours” of materiality you will meet in practice, each anchored in a different reporting regime:
| Type | The question it asks | Direction | Where it is required |
|---|---|---|---|
| Financial (a.k.a. single) | Which sustainability matters could affect the company’s enterprise value? | Outside-in | ISSB (IFRS S1/S2), SASB |
| Impact | How do the company’s activities affect people and the environment? | Inside-out | GRI |
| Double | Both — a topic is material if it meets either test | Both directions | CSRD / ESRS (EU law) |
“Single materiality” is simply another name for the financial-only view, used to contrast it with double materiality. The distinction is not academic: it decides how much a company must disclose. Under the ISSB‘s financial-materiality standards a company reports the sustainability matters that bear on its own value; under the EU’s ESRS and its double-materiality test it must also report its material impacts on the world, even where those impacts carry no near-term financial consequence for the company. Same company, same year — a materially different report, depending on which materiality applies.
The Materiality Assessment
Deciding what is material is not a guess; it is a structured exercise called a materiality assessment (under CSRD, a double materiality assessment). Although the details vary by framework, the shape is consistent: identify the universe of potentially relevant sustainability topics — often framed as impacts, risks and opportunities — gather evidence and engage the stakeholders and experts who understand them, then apply thresholds to judge which topics cross the bar of significance in each direction.
The thresholds themselves differ by direction. Impact significance is judged mainly on the severity of the effect — its scale, scope and how hard it is to remediate — together with, for potential impacts, how likely it is to occur. Financial significance is judged on the magnitude of the effect on the company’s position or value and the probability of it materialising. A topic clears the bar if it is significant enough on either axis; it does not need to be significant on both. Making those judgements explicit, and evidencing them, is what separates a defensible assessment from a box-ticking one.
The output is the list of material topics that sets the scope of the report: only material topics need be disclosed in detail. Historically the result was often plotted on a materiality matrix — a grid with impact significance on one axis and financial significance on the other — though current guidance, especially under CSRD, has moved away from the 2×2 matrix toward clearer thresholds and better-evidenced reasoning. Because it governs report scope, the materiality assessment is increasingly itself subject to assurance: an auditor may check not just the disclosures but whether the company reached its materiality conclusions defensibly. It also reaches across the value chain, not just a company’s own operations — a topic can be material because of what happens at a supplier or in the use of a product, which is why material topics so often sit in the same territory as Scope 3 emissions.
Why Materiality Matters
Materiality is the hinge on which a sustainability report turns. It sets what must be disclosed, which shapes what is assured, which shapes what investors and stakeholders can compare between companies. Two firms using different materiality tests are, in a real sense, answering different questions, which is why comparability across frameworks depends on understanding which materiality each has applied.
The direction of travel is toward convergence without full uniformity. The EU’s double-materiality CSRD and the investor-focused ISSB standards were designed to interoperate, and EFRAG and the ISSB have published joint guidance so that the financial-materiality core aligns and companies are not forced to run two incompatible assessments. Impact reporting under GRI remains the reference for the inside-out view. For a company, the practical questions are which regime it falls under, and therefore which materiality it must satisfy — and, increasingly, how to run a single assessment that can serve more than one of them. Materiality is not static, either: a topic that is immaterial today can become material as the business, the science or the regulation changes, so the assessment is revisited, not settled once.
This movement over time has its own name — dynamic materiality — and it describes how issues migrate between the two directions. Something that starts out as an impact the company has on the world, with no financial consequence, can become financially material as public concern, regulation or physical reality catches up with it. Climate change is the archetype: a company’s emissions were an impact long before carbon prices, disclosure mandates and physical risk made them a matter of enterprise value. Dynamic materiality is the reason the inside-out and outside-in views are not permanently separate lists but two vantage points on the same issues at different stages — and it is a strong argument for assessing both, since today’s impact is often tomorrow’s financial risk.
Common Confusions
- Treating “material” as a synonym for “important”. Materiality is a defined threshold — significant enough to influence a report user’s decisions — not a general sense of importance.
- Mixing up the two directions. Financial materiality is outside-in (how the world affects the company); impact materiality is inside-out (how the company affects the world). A topic can be material one way and not the other.
- Confusing single with double materiality. Single (financial) materiality, used by the ISSB, tests only effects on enterprise value; double materiality, used by CSRD, adds the impact direction. They demand different amounts of disclosure.
- Thinking materiality is fixed. It is reassessed over time; topics move in and out of scope as the business, evidence and rules evolve.
- Mistaking the matrix for the assessment. A materiality matrix is one way to present results; current guidance leans on thresholds and evidence rather than a 2×2 grid, and some frameworks have dropped it.
Frequently Asked Questions
Materiality is the principle that decides which information is significant enough to be disclosed. An item is material if omitting, misstating or obscuring it could reasonably be expected to influence the decisions of the people who rely on the report. The concept comes from financial accounting and auditing, where it separates what must be reported from what is too trivial to matter, and sustainability reporting adopted it as the filter for deciding which environmental, social and governance topics a company must address. What makes it distinctive in sustainability is that it can be assessed in two directions — how sustainability issues affect the company (financial materiality) and how the company affects people and the environment (impact materiality) — and different frameworks require different combinations of the two.
They differ in the direction they test. Financial materiality (also called single materiality) is “outside-in”: it asks which sustainability matters could affect the company’s own enterprise value, protecting investors, and it is the basis of the ISSB’s IFRS S1 and S2 standards. Impact materiality is “inside-out”: it asks how the company’s activities affect people and the environment, judged by severity rather than financial consequence, and it is the basis of GRI reporting. Double materiality combines the two — a topic is material if it meets either the financial or the impact test — and it is the approach embedded in the EU’s Corporate Sustainability Reporting Directive and its ESRS standards. A topic can be material under one direction and not the other, so the choice of materiality determines how much a company must disclose.
A materiality assessment is the structured process a company uses to determine which sustainability topics are material and therefore must be reported. In outline, the company identifies the universe of potentially relevant topics — often expressed as impacts, risks and opportunities — gathers evidence and engages stakeholders and experts who understand them, and then applies thresholds to judge which topics are significant enough to cross the bar in each direction. Under the EU’s CSRD this is specifically a double materiality assessment, testing both financial and impact significance. The output is a defined list of material topics that sets the scope of the report, so the assessment effectively decides what the whole report will and will not cover. Because it is so consequential, the assessment is increasingly subject to external assurance.
It depends on the framework you report under, which in turn depends mainly on your jurisdiction and who requires your disclosures. If you report under the EU’s Corporate Sustainability Reporting Directive and its ESRS standards, you must apply double materiality — assessing both how sustainability issues affect your enterprise value and how your company affects people and the environment. If you report under the ISSB’s IFRS S1 and S2 standards, which many jurisdictions outside the EU are adopting for investor-focused disclosure, you apply financial (single) materiality only. Many companies fall under more than one regime, in which case the practical goal is to run a single, well-evidenced assessment that satisfies the strictest applicable test — usually double materiality — while aligning the financial core with the ISSB so the work is not duplicated.
A materiality matrix is a way of presenting the results of a materiality assessment, typically as a grid with one axis for significance to the business (financial) and another for significance to stakeholders or the environment (impact), on which topics are plotted so the most material ones stand out in one corner. It became a familiar feature of sustainability reports as a quick visual summary. However, current guidance — particularly under the EU’s CSRD — has moved away from the 2×2 matrix, on the grounds that it can oversimplify and that a defensible assessment should rest on clear thresholds and documented evidence rather than the positioning of dots on a chart. The matrix is a communication device, not the assessment itself, and some frameworks now discourage relying on it.
Materiality originates in financial accounting and auditing, where it has long been used to decide which items are significant enough to affect the judgement of someone reading a set of financial statements — small enough errors or omissions are “immaterial” and need not be corrected or disclosed. Sustainability reporting adopted the same underlying idea but broadened it in two ways: it widened the range of users beyond investors to include stakeholders such as employees, communities and regulators, and it added the inside-out, impact direction alongside the traditional outside-in, financial one. The result is that the single accounting concept of “material” has become the organising principle of sustainability disclosure, expressed through the financial, impact and double-materiality tests that today’s frameworks are built around.