An actual value is an emissions figure calculated from your facility's own production data and confirmed by an accredited verifier. A default value is a reference figure the EU sets, based on sector averages, for exporters who don't provide — or can't yet provide — verified data.

Both methods are accepted in CBAM reporting, but which one you use shapes both your reporting workload and your final cost.

The EU deliberately adds a mark-up to default values — the intent is to encourage businesses to verify and report their actual data instead. As a result, default values usually come out higher than your facility's real emissions performance.

In practice, this means that if your production process's actual emissions intensity is below the sector average, using default values forces you to buy more certificates than you actually need.

If you run an energy-efficient, lower-carbon production process, documenting that with verified actual data translates directly into a cost advantage: fewer certificates needed, lower CBAM costs, and more competitive pricing in the EU market.

This isn't a one-off benefit — once your verification infrastructure is in place, it keeps delivering the same advantage every reporting period.

If your data collection and verification infrastructure isn't mature yet, default values can serve as a temporary starting point — but that means accepting a cost disadvantage in the medium term.

If you have reasonable confidence in your production process's emissions performance, investing early in verification usually pays for itself quickly.