Yes. Lack of supplier-specific carbon data doesn’t mean your business has to wait before developing a Scope 3 emissions estimate.
For many SMEs, the practical approach is to start with the information already available in their accounting, purchasing and operational systems.
There are generally three levels of information you can use:
1. Spend-based data
If you know how much your company spends on a particular category—steel, packaging, chemicals, professional services or other purchases—you can apply recognized industry emission factors to estimate the associated emissions.
This is often the easiest place to start, although it provides a relatively high-level estimate.
2. Activity-based data
A better estimate may be possible when you know the physical quantity purchased. For example, tonnes of steel, kilograms of packaging material or tonne-kilometres of freight can be multiplied by appropriate emission factors.
This generally provides a more meaningful estimate than relying solely on dollars spent.
3. Supplier-specific data
As your Scope 3 program develops, you can begin replacing estimates with actual information from key suppliers, such as product carbon footprints or verified product-level emission factors.
Think of Scope 3 measurement as a progression rather than an all-or-nothing exercise:
Spend data → Activity data → Supplier-specific carbon data
For an SME, the objective in year one shouldn’t necessarily be perfect Scope 3 information. A more practical goal is to establish a reasonable baseline, document your assumptions and identify where better information would materially improve the calculation.
Start with your largest purchasing categories and suppliers. Improve the information over time.
You don’t need perfect supplier data to start measuring Scope 3—but you should understand and document the limitations of the data you use.