How to Share Your Carbon Data with Clients: The Complete Supplier Guide
Why Format Matters When You Share Carbon Data
You have measured your emissions, generated a Carbon Passport, and your client is asking for the data. Here is a frustrating reality most suppliers discover the hard way: sending the wrong format, in the wrong units, to the wrong inbox means the questionnaire still doesn't get marked complete — even though you have done the hard part.
This guide covers exactly how to share your carbon data with different client types, in the format they need to close the request.
What Format Does Each Client System Require?
| Client System | What They Need From You |
|---|---|
| SAP Ariba | Numeric tCO2e fields in the questionnaire + verification URL |
| Coupa | Numeric fields + PDF attached to the supplier profile |
| Jaggaer | URL link or PDF uploaded to the ESG supplier section |
| Email questionnaire | PDF attachment + inline key figures in the email body |
| EcoVadis | Carbon data entered separately in the EcoVadis portal |
| Excel sustainability form | PDF + manual entry of key figures into the cells |
In almost every case you need both a PDF (for attachment and email) and a verification URL (for online portals). DeCarbonOPS Carbon Passports include both.
What Are the Exact Numbers Clients Copy Into Their Systems?
Most procurement questionnaires require you to manually enter specific figures into individual fields. Have these ready before you open any portal:
- Scope 1 total (tCO2e) — your direct combustion figure
- Scope 2 total (tCO2e) — your electricity figure; note if location-based or market-based
- Scope 3 total (tCO2e) — your value chain estimate (even if partial)
- Combined total (tCO2e) — Scope 1 + 2 + 3
- Emissions intensity per employee — total tCO2e ÷ headcount
- Emissions intensity per revenue — total tCO2e ÷ annual revenue (in €M)
- Reporting year — confirm it is a complete calendar year
- Methodology statement — "GHG Protocol Corporate Standard, DEFRA 2023 emission factors, self-assessed"
Write these down before opening the portal. Switching between tabs while the questionnaire times out is a common problem.
What Does "Self-Assessed," "Third-Party Reviewed," and "Externally Verified" Mean?
Most questionnaires include a drop-down for verification level. Here is what each means:
| Level | What It Means | Accepted By |
|---|---|---|
| Self-assessed | You calculated internally using a tool or methodology | Most SME questionnaires |
| Third-party reviewed | An external party checked your methodology and inputs | Larger clients, tier 1 suppliers |
| Externally verified | Formal audit by accredited body (like a financial audit) | Listed companies, high-value contracts |
For a first Carbon Passport, you are self-assessed. This is accepted by the vast majority of SME supplier questionnaires. Third-party review is typically required only for higher-tier vendor status or clients with specific contract requirements.
How Do You Share Carbon Data By Email Without a Portal?
When a client sends a carbon questionnaire directly by email — common with smaller enterprise clients — use this structure in your reply:
Subject: Carbon Emissions Data — [Your Company] — [Reporting Year]
Include in the body: your Scope 1 / Scope 2 / Scope 3 totals in tCO2e, combined total, reporting year, methodology statement (GHG Protocol, DEFRA 2023, self-assessed), and your Carbon Passport verification URL. Attach the PDF.
This structure matches what sustainability teams log into internal systems and avoids follow-up requests. Read the full supplier questionnaire guide for how to handle SAP Ariba specifically.
How Do You Keep Your Data Current for Annual Renewals?
Enterprise clients renew sustainability questionnaires annually. Procurement teams are increasingly rejecting carbon data older than 18 months.
The correct approach: generate a new Carbon Passport in DeCarbonOPS each year as soon as your previous year's utility bills are available (typically February–March). Your company profile carries over between years, so the data entry takes 10–15 minutes for a renewal. Then update the URL and figures in each client's portal.
One session per year, covering every client questionnaire you will receive for the next 12 months. That is the maintenance overhead of being a verified, carbon-transparent supplier.
Frequently Asked Questions
What format do clients need for carbon data sharing?
Most clients need two things: a PDF attachment (for email and portal uploads) and a verification URL (for entering into online procurement platforms like SAP Ariba and Coupa). DeCarbonOPS Carbon Passports include both — a permanent public URL and a downloadable PDF.
What specific numbers do clients want when I share carbon data?
Clients typically need: Scope 1 total (tCO2e), Scope 2 total (tCO2e), Scope 3 total (tCO2e), combined total, emissions intensity per employee and per €M revenue, the reporting year, and a methodology statement (GHG Protocol Corporate Standard, DEFRA 2023 emission factors, self-assessed).
What does self-assessed carbon data mean and is it accepted?
Self-assessed means you calculated your emissions internally using a tool or recognised methodology, without an external auditor reviewing the work. It is accepted by the majority of SME supplier questionnaires, including most SAP Ariba and Coupa sustainability assessments. Third-party review is typically only required for larger suppliers or high-tier vendor status.
How do I share my carbon data by email without a procurement portal?
Use a clear subject line (Carbon Emissions Data — [Company] — [Year]), include Scope 1/2/3 totals in the email body, state your methodology, paste your Carbon Passport verification URL, and attach the PDF. This structure matches what procurement teams log into internal tracking systems.
How often do I need to update my carbon data for clients?
Most enterprise clients renew sustainability questionnaires annually, and many are beginning to reject data older than 18 months. Generate an updated Carbon Passport in DeCarbonOPS each year after your previous year's utility bills are available (typically February–March). Renewal data entry takes 10–15 minutes since your company profile carries over.
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