What the Costco SSA Actually Covers
Costco's Supplier Sustainability Assessment (SSA) is sent to suppliers as part of the onboarding and periodic review process. Unlike Walmart Gigaton (which is a commitment platform), the SSA is a structured questionnaire that collects data across four areas:
- Environmental performance (energy, water, emissions, waste)
- Labor and social practices
- Product safety and quality systems
- Business ethics and governance
For manufacturers, the Environmental section is typically the hardest. It asks for specific quantitative data — not just "do you have a policy" but "what were your total Scope 1, 2, and 3 emissions last year."
The Environmental Data Costco Wants
Expect to provide:
- Total energy consumption by source (electricity, natural gas, fuel oil, diesel)
- Renewable energy percentage
- Scope 1 and 2 GHG emissions (tonnes CO2e)
- Scope 3 emissions — at minimum Category 1 (purchased goods) and Category 4 (freight)
- Water withdrawal and discharge by source
- Total waste generated, landfill diversion rate
- Whether you have a third-party verified emissions inventory
You don't fail for not having third-party verification — but suppliers with verified data score materially higher. Costco buyers use SSA scores in supplier evaluation.
How Scoring Works
Costco doesn't publish a formal scoring rubric, but the pattern across SSA responses is consistent:
- Highest scores: quantitative data + documented methodology + third-party verification or certification
- Mid scores: quantitative data without third-party verification
- Low scores: qualitative statements ("we track emissions") without numbers
- Zero: skipped questions or "N/A" on applicable questions
The most common mistake: answering the governance questions well (because they're easy to address with policy documents) while leaving emissions data fields blank. Buyers see that immediately.
Preparing Your Numbers
Most food manufacturers can get their Scope 1 and 2 numbers from utility bills and natural gas invoices — they're direct measurements. Scope 3 is harder because it requires attributing emissions to supply chain spend.
The spend-based approach works well here: use your QuickBooks or ERP export to categorize purchases into materials, freight, and services, then apply DEFRA or EPA emission factors for each category. The result is a defensible Scope 3 estimate that satisfies Costco's SSA without requiring you to collect data from each individual supplier.
Emissa generates a Costco SSA-formatted report directly from your QuickBooks transaction export. Upload once, download the completed emissions section of the SSA with supporting methodology documentation.
Timeline and What to Expect
Costco typically sends SSA requests with a 30–60 day completion window. Don't wait until you get the request — gather your baseline emissions data now so you're not scrambling. If you're in Costco's organic, private label, or premium food categories, expect sustainability requirements to intensify over the next 12–18 months.
Suppliers who respond to SSAs with complete, quantitative answers get re-invited. Suppliers who leave emissions sections blank often don't.