Commitments and Contingencies	12 Months Ended
Mar. 31, 2025
Commitments and Contingencies Disclosure [Abstract]
20. COMMITMENTS AND CONTINGENCIES	20. COMMITMENTS AND CONTINGENCIES We are party to, and may in the future be involved in or subject to, disputes, claims, and proceedings arising in the ordinary course of our business, including some we assert against others, such as environmental, health and safety, product liability, employee, tax, personal injury, and other matters. For certain matters in which the Company is involved for which a loss is reasonably possible, we are unable to estimate a loss. For certain other matters for which a loss is reasonably possible and the loss is estimable, we have estimated the aggregated range of loss as $0 to $71 million. This estimated aggregate range of reasonably possible losses is based upon currently available information. The Company's estimates involve significant judgment, and therefore, the estimate will change from time to time and actual losses may differ from the current estimate. We review the status of, and estimated liability related to, pending claims and civil actions on a quarterly basis. The evaluation model includes all asserted and unasserted claims that can be reasonably identified, including claims relating to our responsibility for compliance with environmental, health and safety laws and regulations in the jurisdictions in which we operate or formerly operated. The estimated costs in respect of such reported liabilities are not offset by amounts related to insurance or indemnification arrangements unless otherwise noted. Environmental Matters We own and operate numerous manufacturing and other facilities in various countries around the world. Our operations are subject to environmental laws and regulations from various jurisdictions, which govern, among other things, air emissions; wastewater discharges; the handling, storage and disposal of hazardous substances and wastes; the remediation of contaminated sites and restoration of natural resources; carbon and other greenhouse gas emissions; and employee health and safety. Future environmental, health and safety regulations may impose stricter compliance requirements on the industries in which we operate. Additional equipment or process changes at some of our facilities, and related capital expenditures, which may be material, may be needed to meet existing or future requirements. The cost of meeting these requirements may be significant. Failure to comply with such laws and regulations could subject us to administrative, civil, or criminal penalties; obligations to pay damages or other costs; and injunctions and other orders, including orders to cease operations. We are involved in proceedings under the U.S. Comprehensive Environmental Response, Compensation, and Liability Act, also known as CERCLA or Superfund, or analogous state provisions regarding our liability arising from the usage, storage, treatment, or disposal of hazardous substances and wastes at a number of sites in the U.S., as well as similar proceedings under the laws and regulations of the other jurisdictions in which we have operations, including Brazil, certain countries in the European Union, and South Korea. Many of these jurisdictions have laws that impose joint and several liability, without regard to fault or the legality of the original conduct, for the costs of environmental, health and safety remediation, natural resource damages, third-party claims, and other expenses. In addition, we are, from time to time, subject to environmental, health and safety reviews and investigations by relevant governmental authorities. For example, during fiscal 2022, we were notified of an investigation into the Novelis Yeongju location by South Korean environmental authorities related to self-reporting by the facility of manufacturing and production emissions above applicable limits. The investigation related to previous investigations at the facility during which certain emissions amounts were identified as above applicable limits triggering self-reporting, and instances in which reporting by a third-party measuring emissions may have inconsistently reported information to the facility, impacting what was reported to regulators. Based on the information learned, Novelis filed a leniency application and voluntarily disclosed to South Korean environmental authorities. The investigation remains ongoing and the Company has booked a reserve for the matter. We have established liabilities based on our estimates for currently anticipated costs associated with environmental matters. We estimate that the costs related to our environmental liabilities as of March 31, 2025, were $38 million, of which $19 million was related to undiscounted clean-up costs, $15 million was associated with an increase in environmental reserves, and $4 million was associated with restructuring actions. As of March 31, 2025, $19 million is included in accrued expenses and other current liabilities and the remainder is within other long–term liabilities in our accompanying consolidated balance sheets. As of March 31, 2024, we reported $38 million of total environmental liabilities in our consolidated balance sheet. Brazil Tax Litigation We are involved in several unresolved tax and other legal claims in Brazil. Total liabilities for disputes and claims were $34 million and $40 million as of March 31, 2025, and March 31, 2024, respectively. As of March 31, 2025, the $34 million is included in other long–term liabilities in our accompanying consolidated balance sheets. Additionally, we have included in the range of reasonably possible losses disclosed above any unresolved tax disputes or other contingencies for which a loss is reasonably possible and estimable. The interest cost recorded on these settlement liabilities offset by interest earned on the cash deposits is reported in other expenses (income), net on the consolidated statements of operations. During prior fiscal years, we received multiple favorable rulings from the Brazilian court that recognized the right to exclude certain taxes from the tax base used to calculate contributions to the social integration program and social security contributions on gross revenues, also known as PIS and COFINS. As a result of these cases, we have the right to apply for tax credits for the amounts overpaid during specified tax years. These credits and corresponding interest can be used to offset various Brazilian federal taxes in future years. The credit amounts, interest calculation, and supporting documentation are subject to further validation and scrutiny by tax authorities for five years after the credits are utilized. Thus, credits recognized may differ from these amounts. In order to qualify for these credits, the Company is required to compile and present verifiable support validating the credits. During fiscal 2022, Novelis applied for and received official authorization from The Special Department of Federal Revenue of Brazil ("Receita Federal") to use the PIS and COFINS credits related to certain periods. Novelis was able to utilize a majority of these credits to offset taxes to be paid in fiscal 2022 and utilized the remaining credits in fiscal 2023. Novelis received a tax notification on July 11, 2024, requesting information for the calculated credits of COFINS in the amount of $43 million, related to the period from 2008 to 2014, and PIS and COFINS in the amount of $28 million, related to the period from 2015 to 2017. If the credits are not sufficiently validated per the request, a portion of the COFINS and PIS and COFINS credits may be disallowed. The Company believes it has sufficient documentation to support the use of the credits.

We are party to, and may in the future be involved in or subject to, disputes, claims, and proceedings arising in the ordinary course of our business, including some we assert against others, such as environmental, health and safety, product liability, employee, tax, personal injury, and other matters. For certain matters in which the Company is involved for which a loss is reasonably possible, we are unable to estimate a loss. For certain other matters for which a loss is reasonably possible and the loss is estimable, we have estimated the aggregated range of loss as $0 to $71 million. This estimated aggregate range of reasonably possible losses is based upon currently available information. The Company's estimates involve significant judgment, and therefore, the estimate will change from time to time and actual losses may differ from the current estimate. We review the status of, and estimated liability related to, pending claims and civil actions on a quarterly basis. The evaluation model includes all asserted and unasserted claims that can be reasonably identified, including claims relating to our responsibility for compliance with environmental, health and safety laws and regulations in the jurisdictions in which we operate or formerly operated. The estimated costs in respect of such reported liabilities are not offset by amounts related to insurance or indemnification arrangements unless otherwise noted.

We own and operate numerous manufacturing and other facilities in various countries around the world. Our operations are subject to environmental laws and regulations from various jurisdictions, which govern, among other things, air emissions; wastewater discharges; the handling, storage and disposal of hazardous substances and wastes; the remediation of contaminated sites and restoration of natural resources; carbon and other greenhouse gas emissions; and employee health and safety. Future environmental, health and safety regulations may impose stricter compliance requirements on the industries in which we operate. Additional equipment or process changes at some of our facilities, and related capital expenditures, which may be material, may be needed to meet existing or future requirements. The cost of meeting these requirements may be significant. Failure to comply with such laws and regulations could subject us to administrative, civil, or criminal penalties; obligations to pay damages or other costs; and injunctions and other orders, including orders to cease operations.

We are involved in proceedings under the U.S. Comprehensive Environmental Response, Compensation, and Liability Act, also known as CERCLA or Superfund, or analogous state provisions regarding our liability arising from the usage, storage, treatment, or disposal of hazardous substances and wastes at a number of sites in the U.S., as well as similar proceedings under the laws and regulations of the other jurisdictions in which we have operations, including Brazil, certain countries in the European Union, and South Korea. Many of these jurisdictions have laws that impose joint and several liability, without regard to fault or the legality of the original conduct, for the costs of environmental, health and safety remediation, natural resource damages, third-party claims, and other expenses. In addition, we are, from time to time, subject to environmental, health and safety reviews and investigations by relevant governmental authorities. For example, during fiscal 2022, we were notified of an investigation into the Novelis Yeongju location by South Korean environmental authorities related to self-reporting by the facility of manufacturing and production emissions above applicable limits. The investigation related to previous investigations at the facility during which certain emissions amounts were identified as above applicable limits triggering self-reporting, and instances in which reporting by a third-party measuring emissions may have inconsistently reported information to the facility, impacting what was reported to regulators. Based on the information learned, Novelis filed a leniency application and voluntarily disclosed to South Korean environmental authorities. The investigation remains ongoing and the Company has booked a reserve for the matter.

We have established liabilities based on our estimates for currently anticipated costs associated with environmental matters. We estimate that the costs related to our environmental liabilities as of March 31, 2025, were $38 million, of which $19 million was related to undiscounted clean-up costs, $15 million was associated with an increase in environmental reserves, and $4 million was associated with restructuring actions. As of March 31, 2025, $19 million is included in accrued expenses and other current liabilities and the remainder is within other long–term liabilities in our accompanying consolidated balance sheets. As of March 31, 2024, we reported $38 million of total environmental liabilities in our consolidated balance sheet.

We are involved in several unresolved tax and other legal claims in Brazil. Total liabilities for disputes and claims were $34 million and $40 million as of March 31, 2025, and March 31, 2024, respectively. As of March 31, 2025, the $34 million is included in other long–term liabilities in our accompanying consolidated balance sheets. Additionally, we have included in the range of reasonably possible losses disclosed above any unresolved tax disputes or other contingencies for which a loss is reasonably possible and estimable. The interest cost recorded on these settlement liabilities offset by interest earned on the cash deposits is reported in other expenses (income), net on the consolidated statements of operations.

During prior fiscal years, we received multiple favorable rulings from the Brazilian court that recognized the right to exclude certain taxes from the tax base used to calculate contributions to the social integration program and social security contributions on gross revenues, also known as PIS and COFINS. As a result of these cases, we have the right to apply for tax credits for the amounts overpaid during specified tax years. These credits and corresponding interest can be used to offset various Brazilian federal taxes in future years.

In order to qualify for these credits, the Company is required to compile and present verifiable support validating the credits. During fiscal 2022, Novelis applied for and received official authorization from The Special Department of Federal Revenue of Brazil ("Receita Federal") to use the PIS and COFINS credits related to certain periods. Novelis was able to utilize a majority of these credits to offset taxes to be paid in fiscal 2022 and utilized the remaining credits in fiscal 2023.

Novelis received a tax notification on July 11, 2024, requesting information for the calculated credits of COFINS in the amount of $43 million, related to the period from 2008 to 2014, and PIS and COFINS in the amount of $28 million, related to the period from 2015 to 2017. If the credits are not sufficiently validated per the request, a portion of the COFINS and PIS and COFINS credits may be disallowed. The Company believes it has sufficient documentation to support the use of the credits.