What follows explains how to reach that 81% without sending one more questionnaire.
There are Sustainability teams in Mexico and Colombia that send an emissions questionnaire to hundreds of suppliers, wait a month and get a handful of answers, almost all of them incomplete. Procurement was not even copied. The analyst who requested the data is left with a spend-based Scope 3 and a committee asking why the number does not move. This is not an isolated case: Sphera, in its 2025 Scope 3 report, surveyed 315 sustainability professionals across 18 industries, and 79% named supplier data availability as a top challenge.
If you already measure all three scopes with the Greenhouse Gas Protocol (GHG Protocol) and handle Category 1 with spend factors, you are right at that point. The next step is to ask primary data from the people who sell to you, and there the work changes in nature: it stops being a spreadsheet exercise and becomes a negotiation. Your supplier serves several customers, each with its own format, and answers first to the one who renews its contract, pays on time or makes its life easier.
The questions that sustainability teams now ask ChatGPT and Perplexity go in that direction: how to get suppliers to measure and report their carbon footprint, which incentives work, how to move from spend to primary data and whom to prioritize first. We answer them in that order.
The premise of everything that follows fits in one sentence. Your suppliers measure carbon when it suits them, not when you ask. Whoever designs that convenience keeps the primary data that strengthens your CDP (formerly Carbon Disclosure Project) response and your conversation with the bank. Before designing it, it helps to agree on what is being measured.
Scope 3 is the set of indirect emissions in a company's value chain, split into 15 categories under the GHG Protocol.
In its 2024 report, CDP calculated that, among the companies that report to it, supply chain emissions are on average 26 times higher than operational emissions. For an industrial corporate, that means its inventory depends on what others report. Without that data, the final number is an estimate that is hard to defend before an auditor.
In practice, Category 1, purchased goods and services, is almost always calculated with the year's spend multiplied by an average factor. It works for a first map. It breaks when the supplier installs a new boiler or changes its electricity contract: your inventory does not find out, because your spend stays the same. A spend-based Scope 3 measures what you pay, not what you emit. The GHG Protocol technical guidance presents the spend-based method as the option for when there is no supplier or activity data, and that difference shows up the day the bank or the auditor asks for support.
For a corporate that already measures all three scopes, most of the inventory sits in the supply chain, and that part is calculated with estimates. In our experience, that is where the conversation with the bank and with CDP gets stuck: a number that cannot be traced back to the supplier is hard to defend, and an inventory built on averages does not reflect what the chain reduces.
The capital exists: Bloomberg counted USD 939 billion in green, social, sustainability and sustainability-linked bonds issued in 2023. What is missing is traceable data that justifies it. In sustainability-linked loans, the margin adjusts based on meeting measurable targets; White & Case reported in 2021 typical adjustments of 2.5 to 15 basis points in leveraged loans. Without data that proves the target, that adjustment is not negotiated.
Inside the company, the conversation gets stuck on one specific point. Finance wants a defensible number. Sustainability calculates it with what it has. Procurement, which talks to suppliers every day, does not have carbon in its indicators. Nobody is negligent: each area answers to what it is measured on. In 2026, the result is still a Scope 3 that is updated once a year, the week before the report, with data that is already months old. Our view: carbon data already enters the credit conversation, and today that data is decided at the Procurement table.
EcoVadis, with data from more than 56,000 companies rated on carbon, found in its Carbon Action Report 2026 that only 4% report primary Scope 3 data. Those who do get an inventory that is defensible before auditors and banks, but they pay with Procurement time, capture formats and follow-up. That cost is real and falls when there is infrastructure to absorb it.
Advantages
Disadvantages
The real tension is that almost none of the disadvantages belong to primary data. They belong to not having somewhere to receive it. Uneven quality is fixed with a single form and validation rules. Follow-up is fixed with a visible record of who responded. The cost of incentives is fixed by segmenting, because not every supplier deserves the same treatment. The cons of primary data are infrastructure cons. That is why an 80-page PDF from a consultancy does not move your CDP Score on its own: it describes the problem elegantly and leaves data capture exactly where it was. A data infrastructure does move it.
The same EcoVadis report found that companies with verified Scope 1 and 2 data are eight times more likely to engage their suppliers on carbon. Those who do not engage them calculate with spend or sector averages, the methods the GHG Protocol leaves for when there is no supplier data. The mechanism you choose defines how much each point of coverage costs and how fast it arrives.
The voluntary questionnaire is the row where almost every corporate starts and where it stays. The supplier already received several similar ones this year and does not see what it gains. A questionnaire without a contract is a favor, and favors do not scale. The clause and the commercial incentive are the rows where the response moves, because they connect the data with something the supplier values. Co-investment works best with critical suppliers that already have a concrete project. Bono enables the last two rows: its infrastructure brings together the supplier form, response tracking and the connection with technology and financing providers, so that the incentive and the data live in the same system.
In programs with hundreds of suppliers, Bono records an 81% response rate. The difference from a standalone questionnaire comes from the design of the exchange, and each additional point becomes primary data coverage inside your inventory.
When the response is low, there is usually a familiar scene behind it: the supplier receives different formats from several customers, the person who should respond is the plant manager who also runs production, and nobody explained what the corporate will do with what they hand over. They answer first to whoever controls their contract. Whoever controls the contract controls the data.
Our position is simple. Supplier data is not requested, it is bought, and the price is not always money. We have supported programs with hundreds of suppliers in the region, and the process that has worked best has four steps.
We start with the Category 1 by spend that you already have, because it works to rank suppliers by estimated emissions and by weight in your purchasing. In the EcoVadis network, the 10% of companies with the most emissions account for 95% of emissions and connect with an average of 72 buyers. Few suppliers explain almost all of your data, and those same suppliers are saturated with requests. You negotiate with them. For the rest, a short form is enough.
This is where the sentence that organizes the whole article lives. Your suppliers measure carbon when it suits them, not when you ask. Your supplier wants to cut costs and sell more. You want to cut costs, be sustainable and have a credible inventory. The design consists of finding where those two lists coincide.
On the economic side, what works is multi-year contracts that ask for the data in exchange for stable volume, preference in bids, early payment at a preferential rate and co-investment in efficiency. The International Energy Agency (IEA) estimates that most of the CO2 reductions to 2030 in its net zero scenario come from technologies already available, so the supplier is not waiting for innovation: it lowers its energy bill with equipment that already exists. On the commercial side, EcoVadis found that suppliers with verified Scope 1 and 2 data have three times as many buyer connections as those with low-reliability data. Measuring brings them customers.
On the non-economic side, what works is training for the first inventory, a single form instead of five, a benchmark against peers in their sector and public recognition. They cost little, and for a supplier without a sustainability team they save weeks of work.
The first round asks for annual electricity and fuel consumption in physical units, the year's output and plant location. Nothing more. With that, a defensible Scope 1 and 2 footprint can be calculated, and the supplier does not need to know what an emission factor is. Asking for it by email and receiving it in Excel reproduces the problem: Excel is an audit risk, not a measurement tool. A platform designed for Fortune 500 companies in English does not solve the data friction in Monterrey or Bogotá either. Bono's infrastructure sends the form, records who responded and consolidates the answers in your inventory. We use short forms, in Spanish, with examples from the supplier's sector and a single deadline. That combination sustains the 81% response we record in programs with hundreds of suppliers.
When the supplier delivers its data, it needs to see what happened with it. We return its footprint against its sector average, and if the data reveals an opportunity, such as high electricity consumption per tonne produced, we connect it with technology providers and financing options. That closed loop is what makes the supplier respond again next year. For you, each response replaces an estimate with primary data, and each financed project lowers the Scope 3 you report afterwards.
Chile combines the Framework Law on Climate Change, Law 21.455, with a carbon neutrality goal for 2050, and a carbon tax of USD 5 per tonne of CO2 that applies to sources emitting 25,000 tonnes or more a year. For example, a supplier with 30,000 taxed tonnes pays USD 150,000 a year, and that payment comes out of its margin. For it, measuring is cost control before it is compliance. Corfo's Green Credit, which refinances long-term loans for renewable energy, energy efficiency and circular economy projects, offers a way to turn those savings into a project.
In Mexico, the friction starts inside the supplier: the electricity consumption data per line lives in an Excel file that someone at the plant updates when they can, and Finance does not see it. The General Law on Climate Change remains in force, but what moves the exporting supplier today is the European Union's Carbon Border Adjustment Mechanism (CBAM), which since 2026, in its definitive regime, requires EU importers of cement, iron and steel, aluminum, fertilizers, electricity and hydrogen to buy and surrender certificates for the emissions embedded in those goods. A steel supplier that exports to Europe will receive requests for emissions data from its customer, and you need that same data for your Category 1.
In Colombia, the national carbon tax, with a 2026 rate that DIAN set at COP 29,070 per tonne of CO2 equivalent, and Law 2169 of 2021, on climate action, which sets minimum targets for carbon neutrality and resilience, are already part of the conversation with suppliers. Exporters also receive data requests from European customers subject to the Corporate Sustainability Reporting Directive (CSRD). After the Omnibus I reform, the CSRD applies to companies with more than 1,000 employees and more than EUR 450 million in turnover, and it caps what they can request from suppliers of up to 1,000 employees. Our view: in LATAM, opacity weighs more than emissions.
Annual electricity and fuel consumption in physical units, the year's output and plant location. With that data, its Scope 1 and 2 are calculated with local factors. Ask for it in a single form and explain what you will use it for: the supplier responds faster when it understands where the information is going.
Yes, and it works better with critical suppliers and with something in return. Include the clause in renewals and bids, define a single format and a date, and offer something concrete: stable volume, preference in the next bid or technical support. A clause without a counterpart generates minimum compliance and low-quality data.
Segment. If the supplier is critical, escalate the issue to Procurement and tie it to the contract renewal. If it is low impact, keep the spend-based estimate and document the assumption, because the GHG Protocol Scope 3 Standard requires disclosing and justifying any exclusion. Review every year who moved to primary data and who did not.
You do not control other customers, but you do control your own load: a single channel, short forms and data that is reused year after year. With Bono, the supplier answers a brief request in Spanish and you see in one place who responded and what is missing. Less friction for them means better data for you.
Take your Scope 3 from spend to primary data with a shared goal across Procurement, Sustainability and Finance. Book 15 minutes with Bono. We will show you where to start with your suppliers before the call ends.: