The CBAM definitive period started on 1 January 2026, and 1 August 2026 is the deadline for the first periodic report under the new regime. European companies in steel, aluminium, cement, fertilisers, hydrogen and electricity — whether importing into the EU or exporting to carbon-aware markets — need to start computing embedded emissions per tonne of product. This article walks through what data MES + EMS must produce, how to map it to PCF (ISO 14067), which tools actually work, what it costs and what the penalties are. Plus a six-week roadmap to the deadline.