Why Your Suppliers Struggle to Report Carbon Data?What to do about it?

Carbon data from your suppliers is the backbone of credible Scope 3.1 reporting, yet most companies can’t get it right. Why?Because suppliers are struggling, and their challenges go deeper than most realise. 

A recent CDP report found that only 41% of suppliers can provide verified carbon data. The rest? Incomplete, inaccurate, or entirely missing. This presents massive obstacles for CSOs, procurement heads, and ESG leaders trying to meet net-zero targets, comply with disclosure mandates, or maintain leadership scores on CDP or EcoVadis. 

Here, we’ll explore the core reasons suppliers struggle with carbon reporting and offer a roadmap for supporting them—because unless you help fix their problems, your Scope 3.1 reporting won't hold up. 

Why Supplier Carbon Data Challenges Matter 

Scope 3.1 emissions, those from purchased goods and services, can make up over 80% of a company’s total emissions. Yet many suppliers either can’t or won’t report them. 

This isn’t just a sustainability problem, it’s a business risk. Poor-quality Scope 3.1 data can: 

• Undermine SBTi target-setting 

• Lower your CDP or ESG rating 

• Lead to regulatory non-compliance 

Common Challenges Suppliers Face 

Despite increasing pressure for climate disclosure, suppliers face real barriers to reporting Scope 3.1 carbon data. 

Here’s what your procurement or sustainability teams need to know: 

• Data Fragmentation: Emissions data  is often scattered across different departments or systems, such as ERP, procurement and finance, within the supplier's organisation, making it difficult to consolidate into a comprehensive report. Suppliers may also     struggle to track data from lower-tier suppliers, further complicating the reporting process. 

• Data Gaps & Inaccuracy: Many suppliers lack the necessary data to accurately calculate their emissions. This includes missing or unreliable energy consumption data, incomplete records of raw materials, and a lack of transparency in production processes. 

• Poor Sub-tier Data: Suppliers may struggle to collect emissions data from lower-tier suppliers (Tier 2, Tier 3, etc.), leading to gaps in the data and making it difficult to calculate a complete and accurate Scope 3.1 carbon footprint. 

• Complex Supply Chains: For suppliers who themselves rely on multiple subcontractors, tracking upstream emissions (Scope 3 for the supplier) becomes highly complex. This further  affects their ability to provide accurate and complete data to their     customers. 

• Confidentiality Fears: Some suppliers are hesitant to share operational data they perceive as sensitive or commercially valuable. Fear of exposing cost structures, manufacturing processes, or competitive weaknesses can limit their willingness to provide detailed emissions information. 

• Limited Resources: Financial and human resource limitations prevent many suppliers from investing in emissions reporting initiatives. For suppliers operating on thin margins, sustainability reporting is often deprioritised in Favor of immediate     operational needs. 

• Low Awareness: Many suppliers, especially smaller firms, are not fully aware of carbon accounting principles or how their activities translate into emissions. Emissions reporting may not yet be integrated into their business processes. 

• Weak Regulations: In regions where mandatory reporting requirements are weak or absent, suppliers may see little incentive to proactively measure and disclose emissions data. 

• Inconsistent Methods: Suppliers often follow different methodologies for tracking emissions, with no standard approach for data collection. This inconsistency makes it difficult for companies to aggregate, compare, or verify emissions data across their     supply chains. 

These problems block emissions visibility and data confidence for your organisation. 

How to Help Suppliers Get It Right

Here’s how leading companies enable supplier emissions data reporting at scale: 

1.Segment Suppliers by Priority 

Not all suppliers are equally important. Focus on Tier 1 suppliers contributing to most of your spend or carbon footprint. Use spend and emission potential data to prioritise where effort yields the highest return. 

2. Embed in Procurement 

Sustainability requirements shouldn’t be an after thought. Include carbon data expectations in RFPs, RFQs, and master service agreements. Set expectations from day one. 

3.Standardise the Ask 

Inconsistent inputs lead to messy outputs. Share standardised templates, recommend emissions factors (e.g., ecoinvent, DEFRA),and guide on data sources. Consider tools like Mavarick that simplify reporting for SMEs. 

4. Build Capacity 

Your suppliers need support. Offer hands-on workshops, self-service training, or access to easy tools. Platforms like Mavarick allow even low-maturity suppliers to begin reporting with guided workflows. 

5.Address Concerns 

Use NDAs or clarify how data will be used. Many suppliers are open to sharing if they understand it won't reveal cost structures or IP. 

6.Follow Up 

A one-time data request won’t work. Use procurement timelines, reminder workflows, and supplier scorecards to drive consistent action and improvement. 

Companies using Mavarick’s supplier data tools saw up to:

• 30% improvement in emissions data completeness within the first reporting cycle 

• 18% drop in Scope 3.1 estimation error 

“Mavarick helped us engage suppliers without overwhelming them. Our Scope 3 reporting improved drastically in onequarter.” 
— CSO, Global Auto OEM 

Want to simplify Scope 3.1 supplier reporting? 

Suppliers struggling with carbon data isn’t a surprise—it’s the norm. But as reporting requirements tighten and disclosure ratings get competitive, you can’t afford bad Scope 3.1 data anymore. 

Conclusion

You need to partner, not just pressure. By understanding supplier roadblocks and enabling them with tools, training, and incentives, you’ll transform your Scope 3.1 reporting from a liability into a competitive edge. 

The bottom line? Fix your supplier data strategy now, or risk falling behind. 

FAQs 

Q: How do I get started with supplier data collection? 
A: Start by mapping high-impact Tier 1 suppliers, then introduce standardised templates and Scope 3.1 expectations. 

Q: What if suppliers don’t have the tools or knowledge? 
A: Provide capacity-building resources or partner with platforms like Mavarick to guide them. 

Q: Is supplier engagement mandatory for SBTi?
‍A: Yes. For most sectors, credible supplier engagement is critical to SBTi target-setting and validation.