Since early this year, around 150 of the country’s largest emitters, responsible for roughly 40% of national emissions, have been in the compliance phase of Vietnam’s carbon market. Once emission allowances are allocated and carry market value, CO2 effectively becomes a new line item in company expenses, directly influencing profit margins and investment decisions. Vietnam’s carbon market roadmap sets the first compliance cycle from January 1, 2025. The 150 highest-emitting facilities in thermal power generation, cement, steel, chemicals and refining have been given allowances for 2025–2026. Focusing on this group is meant to stabilize the system before expanding to roughly 1,000 enterprises after 2028. With tradable allowances, companies must treat CO2 as both an asset and a liability. Emitting more than the allocated amount means buying allowances; emitting less creates surplus units that can be sold. As prices fluctuate, firms must budget for CO₂ just as they budget for fuel or raw materials. International accounting rules often treat emission allowances as intangible assets or special-purpose inventory. Integrating them into corporate accounting introduces new challenges: how to record and value them, and how to manage price volatility. CFOs will now consider carbon costs alongside interest rates, input prices, and exchange-rate risks. […]