The 2027 Scope 3 Data Crunch: How to Get Better Supplier Answers Without Asking for Everything

If your company is preparing for Scope 3 reporting, there is an uncomfortable reality to face: much of the information you need belongs to someone else.

The emissions associated with purchased goods, transportation, waste, business travel, and other value-chain activities often sit across dozens, hundreds, or even thousands of suppliers. Those suppliers may track utility use, fuel purchases, production volumes, or shipping activity—but many do not yet calculate emissions in a form they can readily share.

That gap is becoming harder to ignore as 2027 reporting pressure approaches.

The solution is not to send every supplier a longer spreadsheet. It is to build a focused data process: identify the suppliers and categories that matter most, ask for information they can realistically provide, document what is estimated, and improve the result over time.

Why supplier data is the central Scope 3 challenge

Scope 3 includes indirect emissions across a company’s value chain. The Greenhouse Gas Protocol organizes those emissions into 15 categories and provides multiple calculation methods for categories such as purchased goods and services, fuel- and energy-related activities, waste, transportation, business travel, and employee commuting.[3]

Unlike Scope 1 and Scope 2 data, however, Scope 3 information usually cannot be pulled from one company’s utility accounts or facility records. It has to be assembled from procurement systems, invoices, logistics records, employee activity, industry averages, and supplier submissions.

The primary-data gap remains significant. EcoVadis and Kearney’s 2026 Carbon Action Report draws on carbon ratings from 56,000 companies. It found that 56% reported Scope 1 and Scope 2 data, 40% shared estimate-based Scope 3 data, but only 4% reported primary Scope 3 data.[1]

That does not mean companies must wait for perfect information. It means they need a disciplined way to distinguish between measured data, supplier-specific estimates, and broad averages.

Why 2027 changes the conversation

California’s climate-disclosure process is one reason supplier requests are likely to accelerate. A July 2026 California Air Resources Board workshop previewed a phased Scope 3 approach under SB 253. The initial concept focused on five categories: purchased goods and services, fuel- and energy-related activities, waste generated in operations, business travel, and employee commuting.[2]

The proposal also called for companies to disclose their accounting methods, data types, exclusions, and the percentage of emissions calculated using primary data.[2] The rulemaking was still in the pre-proposal stage at the time of the workshop, so companies should continue monitoring the final requirements.

Even suppliers that are not directly covered by a disclosure law may feel its effects. Large customers cannot calculate value-chain emissions without requesting information from vendors, contractors, landlords, logistics providers, and other business partners.

As a result, emissions data is becoming part of ordinary commercial activity. It may appear in:

• Supplier questionnaires
• Requests for proposals
• Contract renewals
• Vendor scorecards
• Customer ESG reviews
• Investor or lender due diligence

For suppliers, the ability to respond with organized, traceable information may become a competitive advantage. For reporting companies, the ability to collect that information efficiently will determine whether Scope 3 becomes a repeatable process or a recurring fire drill.

Do not ask every supplier for everything

A common first instinct is to distribute one comprehensive questionnaire across the entire supply base. That may create plenty of activity without producing much usable data.

A better approach begins with prioritization.

EcoVadis found that 10% of companies in its network accounted for 95% of emissions.[1] The exact concentration will differ by organization, but the lesson is broadly useful: a relatively small group of suppliers or purchasing categories may drive a large share of the footprint.

Start by screening suppliers according to factors such as:

• Annual spend
• Type and volume of goods purchased
• Energy intensity of the supplier’s industry
• Transportation distance and mode
• Strategic importance
• Availability of supplier-specific information
• Contract timing and the opportunity to add reporting requirements

This creates a practical engagement sequence. High-impact suppliers receive more detailed requests and support. Lower-impact suppliers can initially be covered by appropriate secondary data or spend-based estimates, with the method and limitations clearly documented.

The goal is not to ignore the rest of the supply chain. It is to direct limited time toward the data improvements most likely to change the result.

Ask for operational records before asking for a perfect footprint

Many suppliers will not have a verified product carbon footprint ready to send. They may still have useful source data.

Depending on the category and calculation method, that information could include:

• Electricity and natural-gas use
• Fuel purchases
• Production quantities
• Material weights
• Waste volumes and disposal methods
• Shipment weights, distances, and transportation modes
• Facility location and reporting period
• Existing Scope 1 and Scope 2 inventories
• The methodology, boundaries, and emissions factors used

These records are often already maintained for billing, accounting, production, or logistics. Asking for familiar operational data can generate a better response than asking a supplier to perform an unfamiliar carbon calculation on short notice.

It also makes the process more transparent. Your team can record whether a number came from a meter, an invoice, a supplier estimate, or an industry average—and apply the appropriate calculation method.

Build a data-quality ladder

Scope 3 reporting should not be treated as a choice between perfect supplier data and no report at all. A staged model is more realistic.

Level 1: Spend-based estimates

Use purchasing data and category-level emissions factors to establish an initial baseline. This can help identify hotspots, but the result may shift with price changes and may not reflect the operational performance of an individual supplier.

Level 2: Activity-based estimates

Replace spend with physical activity where possible: kilograms of material, miles traveled, gallons of fuel, kilowatt-hours used, or tons of waste. This generally brings the calculation closer to the underlying source of emissions.

Level 3: Supplier-specific operational data

Collect energy, fuel, production, or logistics data associated with the supplier, facility, or product. Record the reporting period, boundaries, units, and allocation method.

Level 4: Verified supplier emissions data

Use supplier inventories or product-level figures supported by a defined methodology and, where appropriate, independent assurance.

Not every category or supplier will reach Level 4 immediately. The important step is to label the data quality honestly and create a plan for moving the highest-impact areas upward.

That distinction matters. EcoVadis reports that companies relying on low-reliability supplier data showed a median Scope 3 footprint equal to 2.5 times their operational footprint, compared with 6.8 times among companies using high-reliability or verified data. The report describes the difference as a possible 2.7-times underestimation.[1]

In other words, better data may initially make the footprint larger. That is not a failure. It is a more credible baseline for setting priorities and measuring progress.

Make every request easier to answer

Supplier engagement improves when the request is specific, proportionate, and repeatable.

A useful request should explain:

1. Why the information is needed. Connect the request to a customer requirement, disclosure process, or emissions inventory.
2. What period it covers. Specify calendar year, fiscal year, or another reporting window.
3. Which business unit, site, product, or service is included. Avoid unclear organizational boundaries.
4. Which data fields are required. Include units, file formats, and definitions.
5. Whether estimates are acceptable. Ask suppliers to identify assumptions and estimation methods.
6. How the data will be used and protected. Address confidentiality and access where appropriate.
7. Who can answer questions. Give suppliers a verified human contact rather than leaving them to interpret the request alone.
8. When updates will be required. Turn the request into a cadence, not a one-time scramble.

Before distributing the request broadly, test it with a small group of suppliers. Their questions will reveal unclear terms, unavailable fields, and unrealistic timelines. Revise the template based on what you learn.

Create one system of record

Supplier engagement is only half the challenge. The information also needs to remain usable after it arrives.

If responses are stored across email threads, spreadsheets, shared drives, and procurement platforms, each reporting cycle begins with another search. A stronger process keeps the source data, supporting documents, calculations, assumptions, and versions connected.

For each record, capture:

• Supplier and facility
• Reporting period
• Scope 3 category
• Data source and owner
• Original unit and normalized unit
• Calculation method
• Emissions factor and source
• Allocation rule
• Estimate or primary-data status
• Review notes and approval date
• Missing fields and follow-up status

This creates the audit trail needed to explain not just the final number, but how the number was produced.

Better Scope 3 data starts with better operational data

The companies best prepared for 2027 will not necessarily be the ones that surveyed the most suppliers. They will be the ones that know where emissions are concentrated, what evidence supports each calculation, and which gaps matter enough to address first.

That requires a process that can:

• Bring utility, operational, and supplier information together
• Normalize records across facilities and reporting periods
• Separate measured data from estimates
• Preserve assumptions and supporting documentation
• Produce consistent outputs for customers, regulators, and internal teams
• Improve data quality without rebuilding the entire inventory each year
• Verdafero helps sustainability, facilities, and finance teams make emissions reporting faster and easier to trust. Verdafero InSights, its patented utility monitoring software, securely tracks, analyzes, and reports utility data across properties. Combined with sustainability consulting and professional engineering expertise, it supports fast, accurate Scope 1, 2, and 3 emissions reporting and helps teams identify efficiency opportunities.

Preparing for more Scope 3 requests—or struggling to organize the utility data you already have? Visit Verdafero’s website to learn more and schedule a demo. See how utility data can become a clearer foundation for emissions reporting and better decisions.

Sources

[1] Carbon Action Report 2026 | EcoVadis

[2] CARB Workshop for California Climate Disclosure Rule (SB 253): Key Takeaways | Mintz

[3] Scope 3 Calculation Guidance | Greenhouse Gas Protocol