How to Drive Supplier Engagement for Reliable Sustainability Data Collection

There are growing pressures on businesses to take sustainability seriously across their products and supply chains. Your clients or investors may be pushing for a genuine sustainability agenda. Regulations like the EU’s ESPR may be imposing requirements on the sustainable design of your products. CBAM may be requiring you to account for the carbon embedded in products you import or export to the EU. Or your own leadership team may have set decarbonisation targets that require a clear baseline. Whatever the driver, there is a good chance you will need to commission an LCA study, produce an EPD, or calculate embedded emissions for CBAM compliance, all of which rely on reliable, representative environmental data for your products.

To get figures that genuinely reflect your product (rather than relying on generic industry averages or, in the case of CBAM, punitive default emission values), you need actual data from your supply chain. That means engaging your suppliers: understanding their processes, collecting their production data, and building the kind of relationship where that information flows reliably.

This is where most companies hit a wall. The instinct is to send a questionnaire, ask for energy consumption, material compositions, and waste data, then wait. What comes back is often incomplete, inconsistent, or nothing at all. The supplier does not understand what is being asked, does not see why it matters to them, or simply does not have the data in the format you need.

This is not a supplier problem. It is an engagement problem. The quality of the data you receive is directly tied to the quality of the relationship behind it. This guide explains how to approach supplier engagement in a way that delivers the data you need for LCA, EPD, and CBAM work, while building relationships that continue to pay off well beyond a single assessment.

Contents

1. Why primary data matters for LCAs, EPDs & CBAM
2. Why most supplier surveys fail
3. Map what you already know
4. Prioritise your suppliers strategically
5. Approach suppliers as partners, not data sources
6. Make requests specific, simple, and worthwhile
7. Build trust through transparency
8. Think long-term, not transactional
9. From better data to better decisions
10. The big picture: moving toward sustainable supply chain management
11. FAQs

Why primary data matters for LCAs, EPDs & CBAM #

An LCA model typically uses a mix of primary and secondary data. Secondary data is sourced from online databases such as ecoinvent, LCA Commons, or Agribalyse, representing generic averages compiled from multiple geographically dispersed facilities, technologies, and time periods. Primary data, on the other hand, is measured directly from your own foreground processes and collected from your suppliers on their operations. When a supplier provides their actual electricity consumption per tonne of output, their specific material composition, or the real transport route from their facility to yours, the model shifts from a generic estimate to a reflection of your actual supply chain.

The balance between primary and secondary data affects model reliability and the certainty of the conclusions you can draw from it. A model built heavily on secondary data may not reflect the actual environmental footprint of your specific product, risking unreliable decisions about where to focus improvements. For EPDs, PCRs (within standards such as EN 15804) generally require primary data for foreground processes under the manufacturer’s control, and verifiers check that the declared product’s foreground is represented by that primary data rather than generic data. For CBAM, installation-specific emissions data for precursor materials is required, and if your supplier cannot provide it, your importer must use default values that are almost always higher than reality.

In each case, the accuracy of the data from your supply chain directly affects the credibility and commercial value of the assessment. Given time and feasibility constraints, however, not every process needs primary data from day one. The practical starting point is to identify where emissions are expected to concentrate and prioritise supplier data collection there first.

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Why most supplier surveys fail #

Data requested from suppliers can sometimes turn out to be of worse quality than the secondary data already available from databases, especially when the request is poorly designed or the relationship behind it is weak. Research backs this up. A study by Miah et al. (2017), which documented Nestle’s experience of collecting LCI data from 67 ingredients and packaging suppliers, found that only 55% returned the questionnaire. Critically, the study found that the level of supplier participation depended largely on trust and the strength of existing relationships. The reasons behind low response rates, both in that study and in wider practice, tend to follow a common pattern.

No context. The supplier receives a data request with no explanation of what it feeds into or what happens next. Without that context, the request simply gets deprioritised in favour of more pressing demands.

Too broad or too technical. Asking for data across an entire product range overwhelms the supplier, and using LCA-specific terminology without explanation makes it harder still. For many suppliers, particularly SMEs, completing an LCI questionnaire to the required level of detail is either a completely new exercise or one presented in unfamiliar technical language.

Commercial sensitivity. Suppliers may be reluctant to share production data for fear of it being used against them commercially. Despite reassurances such as non-disclosure agreements, resistance from some suppliers still remains.

No clear benefit. The supplier sees the effort required and no return. They are giving you something valuable and receiving nothing in exchange.

Survey fatigue and capacity gaps. Suppliers serving multiple customers receive sustainability questionnaires in different formats, each asking for slightly different things. Many, particularly SMEs, simply do not have the internal systems or expertise to respond accurately.

One-off framing. The request arrives as a one-time project, and because there is no ongoing relationship or expectation attached to it, the supplier puts it at the bottom of the pile.

The data usually exists somewhere in the supplier’s utility bills, production records, and purchasing systems. The challenge is creating the conditions in which they are willing and able to share it.

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Map what you already know #

Before approaching any of your suppliers, start by understanding what information you already have access to internally. Apart from the data you control directly from your own facility, including energy use, production volumes, scrap rates, waste streams, and transport records, this process involves reviewing all of your supplier-related purchasing information: what you buy, in what quantities, who supplies it, and how much it costs. This is your bill of materials, and it provides the foundation for approaching suppliers with confidence, demonstrating competence and respect for their time.

Once you have gathered this information, the next step is to run a screening assessment to identify potential hotspots for environmental impact. If your organisation already conducts carbon emissions reporting, the figures calculated for purchased goods and services under Scope 3 using spend or industry-average data may already highlight hotspots in your supply base. Alternatively, you can run an initial screening LCA using proxy data from LCA databases to estimate where environmental impacts are concentrated upstream in your supply chain. For most manufactured products, a small number of input materials account for the majority of the impact, and identifying those hotspots before engaging any suppliers ensures your efforts are targeted where they will make the biggest difference to the accuracy of your LCA model, EPD, or CBAM calculations.

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Prioritise your suppliers strategically #

From the results of the screening assessment, you will have a clearer picture of where to narrow down your focus. However, you do not need data from every supplier identified on day one. Engaging them all simultaneously leads to shallow engagement and poor quality data. The aim, instead, is to start building trust with a focused group of key suppliers, ensuring you get reliable, timely data while laying the groundwork for closer collaboration over time.

Selecting the top 5 to 10 suppliers identified in your screening process is a sensible starting point, as these typically account for the majority of your purchased goods’ environmental footprint. Getting the engagement right with those relationships first allows you to learn what works, what does not, and where gaps still remain, before expanding the exercise to reach others.

A significant portion of your spend on materials might also be coming from relatively low-carbon sectors, however, which is why screening for potential high-emitters across your supply base, such as metals, chemicals, or energy-intensive processing, is just as important. These materials can be disproportionately impactful even when they represent a smaller share of your total spend.

It is also worth noting that smaller suppliers with fewer competing demands can sometimes be easier to engage with initially and more eager for potential collaboration than the larger ones, who may already be fielding many similar requests. Tailoring requests to a larger supplier might therefore require more effort and time to get engagement started in the first place.

The screening assessment ultimately gives you the evidence base for making these decisions. Rather than guessing, you can point to the data and say: these five materials account for 80% of our product’s carbon footprint, and these are the suppliers we need to talk to first.

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Approach suppliers as partners, not data sources #

Getting in touch with a supplier for the first time and simply asking them to send you whatever you need is unlikely to yield positive results. Shifting to an approach where you treat them as partners rather than data sources changes the dynamic entirely.

Start with context. Explain the “why”: what is the data supposed to feed into, and what is the commercial driver behind it? Is it for an LCA study, an EPD, a CBAM calculation, or ESPR compliance? Suppliers respond to specific context rather than vague requests, especially when they may be sharing confidential information about their internal processes.

Show what is in it for them. Transparency and traceability across a company’s operations and supply chains are increasingly sought by different stakeholders, including other customers requesting this data due to growing regulatory pressure or internal sustainability improvements, as well as consumers, investors, and governmental bodies. Environmental performance data is therefore becoming a competitive differentiator for suppliers, and those who can monitor and share it efficiently are increasingly winning contracts over those who cannot. Setting up the systems to do this is, in fact, just as much in their interest as it is in yours.

Offer something in return. On top of the benefits that the supplier could achieve by setting up the systems to monitor this type of data, make sure you also have your own input in returning the favour. Share the results of your assessment with them, show them where their material sits in the overall footprint, and highlight any particular hotspots that are directly relevant to them. Ultimately, this opens up conversations about shared challenges and drives longer-term collaboration, creating opportunities for more resilient supply chains. Beyond conventional financial incentives, deeper collaboration can also help with standardising practices, reducing work duplication, and sharing innovative ideas that drive further improvements. Miah et al. (2017) found that this kind of mutual benefit was one of the leading motivations for suppliers to engage with data requests in the first place.

Be honest about the effort. The data collection process can be time and resource-consuming, and it is important to acknowledge that openly rather than glossing over it. Offer them help in finding the most manageable and efficient approach for their specific situation rather than expecting them to figure it out alone, and if you have verified tools or templates that can support the process, share them upfront for encouragement.

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Make requests specific, simple, and worthwhile #

Once you have set the context and presented the potential benefit-share model that could get their attention and encourage collaboration, the practical data requests themselves need to be well designed to not lose the momentum you have built in the relationship.

Ask briefly and simply for total figures, not normalised ones. Request exactly the information needed, nothing more. If you simply need their electricity consumption per tonne of output for a specific product line, ask for the total electricity usage in kWh from their utility bills and the corresponding production volume of the product in question. Requests for ready-to-use normalised figures or LCA-specific outputs are unlikely to be answered and are likely to be ignored. Where possible, an exemplary completed questionnaire or pre-filled template can be provided to show exactly what a response should look like, and for any more complicated requests, tips or further instructions can be included directly in the spreadsheet wherever they might be useful. Particularly for smaller suppliers, who may not have the internal systems to pull the data together, offering a short call to walk through the request or help them extract the information from their utility bills and production records might cost you an hour and can save weeks of back and forth.

Be clear about timelines. Give the supplier a reasonable deadline and explain why it matters. If a verification audit is scheduled for a specific month, or if a CBAM reporting deadline is approaching, say so. Urgency with context is motivating, whereas urgency without context is irritating.

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Build trust through transparency #

Trust means that the supplier believes you will use their data responsibly, that you will not use it against them commercially, and that the effort they invest in the process will be valued.

Be transparent about how the data will be used. If the data feeds into a published EPD, or will be seen by a third-party verifier, explain it and provide the details of the process. Suppliers are far more willing to share sensitive production data when they understand exactly where it goes and who sees it.

Maintain honest dialogue when challenges arise. If the data a supplier provides does not look right, or if there are gaps, raise it directly and collaboratively. “This figure looks lower than we would expect for this process, can we walk through how it was calculated?” is very different from “this data is wrong.” Highlighting any concerns or issues about their data in a constructive way can also strengthen the relationship. When you raise problems collaboratively rather than critically, the supplier begins to see you as a reliable partner who is invested in getting things right, which helps secure the relationship long-term.

Follow through on commitments. If you promised to share the results of the assessment, do it. If you said you would only request data once a year, acknowledge and honour that. Broken commitments erode trust quickly, and once a supplier loses confidence in the process, re-engagement becomes significantly harder than the first round ever was.

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Think longer-term, not transactional #

The biggest mistake companies make with supplier data collection is treating it as a one-off project. You commission an LCA, collect the data, file the report, and move on. Two years later, you need updated figures for a new EPD or a CBAM declaration, and you end up starting the whole engagement process from scratch.

Building data requests into your regular procurement cycle instead, for example by requesting updated figures annually or whenever major sourcing or process changes occur, turns supplier engagement from a standalone sustainability project into a normal part of how you manage your supply chain. It also signals to the supplier that this is a permanent expectation, not a passing initiative, which in itself encourages them to invest in the capacity to respond properly.

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From better data to better decisions #

This long-term approach to supplier engagement leads not only to a more accurate assessment, such as an LCA or EPD that will withstand third-party verification or a CBAM declaration that avoids punitive default values, but the benefits extend further than that, having a more holistic effect across the business.

Identifying real reduction opportunities. Generic data tells you what a typical process looks like, whereas primary data tells you what your actual supply chain looks like. That specificity allows you to identify genuine hotspots and target changes where they will make the most difference. Importantly, identifying a high-impact supplier does not necessarily mean the answer is to replace them. Sharing your findings with that supplier gives them the opportunity to reduce their impacts instead, which benefits not only your products but every other customer they serve across multiple supply chains.

Stronger commercial relationships. Suppliers who have invested time in sharing data and understanding your environmental goals become more than transactional vendors. They become partners with a shared interest in outcomes, which opens the door to joint problem-solving, shared investment in efficiency improvements, and collaborative innovation that neither party could achieve alone.

Supply chain resilience. The visibility that comes from deeper supplier engagement also helps you identify risks earlier, such as dependency on a single source for a high-impact material, exposure to regions with volatile energy grids, or reliance on processes that may face regulatory pressure in the coming years.

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The big picture: moving toward sustainable supply chain management #

Everything described in this article, from mapping your supply chain and prioritising key suppliers to building collaborative relationships and using data to inform decisions, is, in practice, the foundation of sustainable supply chain management.

Most businesses that commission an LCA or EPD start by thinking about a single product assessment. However, the process of engaging suppliers, understanding how your products are made, and using that knowledge to inform sourcing and design decisions naturally evolves into something broader. It becomes a way of managing your supply chain with environmental impact as a core consideration alongside cost, quality, and reliability.

This shift, from one-off assessment to ongoing supply chain management, is where the real value lies. It is how companies move from reactive compliance to proactive improvement, and how supplier data collection ultimately transforms from an administrative task into a strategic capability.

How Below280 can help

At Below280, supplier data collection is a core part of the LCA, EPD, and CBAM work we deliver for manufacturers. We know from experience that the quality of the final assessment depends on the quality of the supplier engagement behind it.

We can help you design and manage the supplier engagement process, from identifying which suppliers to prioritise through to structuring the data request, supporting suppliers who need guidance, and incorporating the data into a robust LCA model. Whether you are starting your first product assessment or looking to improve the data quality behind an existing one, get in touch and we can discuss how to approach it.

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FAQs #

What if my supplier refuses to share data or cannot provide what I need?

This is common, especially with smaller or less mature suppliers, and it should not stop you from progressing. LCA standards such as ISO 14040 and ISO 14044 allow the use of secondary data where primary data is unavailable, so the practical approach is to start with what you can get and improve iteratively. For suppliers that are reluctant due to confidentiality concerns, non-disclosure agreements, anonymisation of data in published outputs, and clear communication about how the data will be used can help build the trust needed for them to participate in future rounds.

How do I handle supplier confidentiality concerns?

The best approach is to be transparent from the start about who will see the data and how it will be used. Offering to sign a non-disclosure agreement, anonymising data in any public outputs (such as EPDs), and limiting the data request to what is genuinely needed for the assessment all help. Where suppliers are still reluctant, an intermediary such as an LCA consultant can sometimes hold the data on their behalf, providing only aggregated outputs back to you.

How long does it typically take to collect supplier data for an LCA?

The first round of supplier data collection usually takes between two and five months, depending on the number of suppliers involved, the complexity of the supply chain, and the maturity of the supplier relationships. Subsequent rounds are typically significantly faster, often completed in a few weeks once suppliers understand what is needed and have systems in place to respond.

How often should I request updated supplier data?

Annually is a good starting point, aligned with your own reporting or assessment cycle. You should also request updates whenever there is a significant change in the supplier’s process, energy source, or material inputs. Building this into your regular procurement review makes it part of the normal business rhythm rather than a separate exercise.

How do I prioritise which suppliers to engage with first?

The most effective approach is to run a screening assessment using spend-based or industry-average data to identify which materials and suppliers contribute most to your product’s environmental footprint. Focus first on the top 5 to 10 suppliers by impact, which typically account for the majority of the footprint, and also consider suppliers in emission-intensive sectors such as metals, chemicals, or energy-intensive processing, even if they represent a smaller share of your total spend.

Does Below280 manage the supplier engagement process directly?

Yes. As part of our LCA, EPD, and CBAM projects, we work directly with your suppliers to collect the data we need. We handle the communication, provide guidance and templates, and ensure the data meets the quality requirements of the assessment, which takes the burden off your team while maintaining your supplier relationships.

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