Ero Copper Corp.

PRELIMINARY NOTES

Date of Information

In this Annual Information Form (“AIF”), Ero Copper Corp., together with its subsidiaries, as the context requires, is referred to as “Ero”, “Ero Copper” or the “Company”. All information contained herein is presented as at December 31, 2024, unless otherwise stated.

Currency

All dollar amounts in this AIF are expressed in Canadian dollars, except as otherwise indicated. References to “$” or “dollars” are to Canadian dollars, references to “US$” and “USD” are to US dollars and references to “R$” and “BRL” are to Brazilian Reais.

Cautionary Note Regarding Forward Looking Statements

This AIF contains “forward-looking statements” within the meaning of the United States Private Securities Litigation Reform Act of 1995 and “forward-looking information” within the meaning of applicable Canadian securities legislation (collectively, “forward-looking statements”). Forward-looking statements include statements that use forward-looking terminology such as “may”, “could”, “would”, “will”, “should”, “intend”, “target”, “plan”, “guidance”, “strategy”, “model”, “expect”, “budget”, “estimate”, “forecast”, “schedule”, “anticipate”, “believe”, “continue”, “potential”, “view”, “assume” or the negative or grammatical variation thereof or other variations thereof or comparable terminology. Forward-looking statements may include, but are not limited to, statements with respect to Mineral Reserve and Mineral Resource (as defined below) estimates; targeting additional Mineral Resources and expansion of deposits; capital and operating cost estimates and economic analyses (including cash flow projections), including those from the Caraíba Operations Technical Report (as defined below), the Xavantina Operations Technical Report (as defined below) and the Tucumã Project Technical Report (as defined below); the Company’s expectations, strategies and plans for the Caraíba Operations (as defined below), the Xavantina Operations (as defined below), the Tucumã Operations (as defined below) and the Furnas Project (as defined below), including the Company’s planned exploration, development, construction and production activities; the results of future exploration and drilling; estimated completion dates for certain milestones; successfully adding or upgrading Mineral Resources and successfully developing new deposits; the costs and timing of current and future exploration, development and construction including but not limited to the Deepening Extension Project (as defined below) at the Caraíba Operations; the duration of the ramp-up process and timing of commercial production at the Tucumã Operations; the timing and amount of future production at the Caraíba Operations, the Tucumã Operations and the Xavantina Operations; the timing, receipt and maintenance of necessary approvals, licenses and permits from applicable governments, regulators or third parties; expectations regarding consumption, demand and future price of copper, gold and other metals; future financial or operating performance and condition of the Company and its business, operations and properties, including expectations regarding liquidity, capital structure, competitive position and payment of dividends; the possibility of entering judgments outside of Canada; expectations regarding future currency exchange rates; and any other statement that may predict, forecast, indicate or imply future plans, intentions, levels of activity, results, performance or achievements.

Forward-looking statements are subject to a variety of known and unknown risks, uncertainties and other factors that could cause actual results, actions, events, conditions, performance or achievements to materially differ from those expressed or implied by the forward-looking statements, including, without limitation, risks related to:

•copper and gold prices are volatile and may be lower than expected;

•mining operations are risky;

•mining operations require geologic, metallurgic, engineering, title, environmental, economic and financial assessments that may be materially incorrect and thus the Company may not produce as expected;

•geotechnical, hydrological and climatic events could suspend mining operations or increase costs;

•actual production, capital and operating costs may be different than those anticipated;

•the Company’s financial performance and results of operations are currently dependent on the Caraíba Operations and the successful ramp up of the Tucumã Operations;

•infectious diseases may affect the Company’s business and operations;

•changes in climate conditions may affect the Company’s operations;

•currency fluctuations can result in unanticipated losses;

•the successful operation of the Caraíba Operations, the Xavantina Operations and the Tucumã Operations depends on the skills of the Company’s management and teams;

•operations during mining cycle peaks are higher cost;

•title to the Caraíba Operations, the Xavantina Operations, and/or the Tucumã Operations may be disputed;

•the Company may fail to comply with the law or may fail to obtain or renew necessary permits and licenses;

•the failure of a tailings dam could negatively impact the Company’s business, reputation and results of operations;

•compliance with environmental regulations can be costly;

•social and environmental activism can negatively impact exploration, development, construction and mining activities;

•the construction and start-up of new mines and projects at existing mines is subject to a number of factors and the Company may not be able to successfully complete new construction projects;

•land reclamation and mine closure requirements may be burdensome and costly;

•the mining industry is intensely competitive;

•inadequate infrastructure may constrain mining operations;

•operating cash flow may be insufficient for future needs;

•fluctuations in the market prices and availability of commodities and equipment affect the Company’s business;

•the Company is subject to restrictive covenants that limit its ability to operate its business;

•the Company’s indebtedness could adversely affect its financial condition and prevent the Company from fulfilling its obligations under debt instruments;

•the Company may not be able to generate sufficient cash to service all of its indebtedness and may be forced to take other actions to satisfy its obligations under such indebtedness, which may not be successful;

•counterparties may default on their contractual obligations to the Company;

•a failure to maintain satisfactory labour relations can adversely impact the Company;

•the Company’s insurance coverage may be inadequate to cover potential losses;

•it may be difficult to enforce judgments and effect service of process on directors, officers and experts named herein;

•the directors and officers may have conflicts of interest with the Company;

•future acquisitions may require significant expenditures and may result in inadequate returns;

•disclosure and internal control deficiencies may adversely affect the Company;

•failures of information systems or information security threats can be costly;

•the Company may be subject to costly legal proceedings;

•the Company may be subject to shareholder activism;

•product alternatives may reduce demand for the Company’s products;

•a lowering or withdrawal of the ratings assigned to the Company’s debt securities by rating agencies may increase the Company’s future borrowing costs and reduce its access to capital;

•the Company’s Brazilian operations are subject to political and other risks associated with operating in a foreign jurisdiction;

•the Company may be negatively impacted by changes to mining laws and regulations;

•a failure to maintain relationships with the communities in which the Company operates and other stakeholders may adversely affect the Company’s business;

•inaccuracies, corruption and fraud in Brazil relating to ownership of real property may adversely affect the Company’s business;

•the Company is exposed to the possibility that applicable taxing authorities could take actions that result in increased tax or other costs that might reduce the Company’s cash flow;

•inflation in Brazil, along with Brazilian governmental measures to combat inflation, may have a significant negative effect on the Brazilian economy and also on the Company's financial condition and results of operations;

•foreign exchange rate instability may have a material adverse effect on the Brazilian economy;

•the Company’s operations may be impaired as a result of restrictions to the acquisition or use of rural properties by foreign investors or Brazilian companies under foreign control;

•recent disruptions in international and domestic capital markets may lead to reduced liquidity and credit availability for the Company;

•the Company may be responsible for corruption and anti-bribery law violations;

•investors may lose their entire investment;

•dilution from equity financing could negatively impact holders of the common shares of the Company

(the “Common Shares”);

•equity securities are subject to trading and volatility risks;

•sales by existing shareholders can reduce share prices;

•the Company does not currently intend to pay dividends;

•public companies are subject to securities class action litigation risk;

•if securities or industry analysts do not publish research or publish inaccurate or unfavourable research about the Company’s business, the price and trading volume of the Common Shares could decline; and

•global financial conditions can reduce the price of the Common Shares.

This list is not exhaustive of the factors that may affect any of the Company’s forward-looking statements. Although the Company has attempted to identify important factors that could cause actual results, actions, events, conditions, performance or achievements to differ materially from those contained in forward-looking statements, there may be other factors that cause results, actions, events, conditions, performance or achievements to differ from those anticipated, estimated or intended.

Forward-looking statements are not a guarantee of future performance. There can be no assurance that forward-looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Forward-looking statements involve statements about the future and are inherently uncertain, and the Company’s actual results, achievements or other future events or conditions may differ materially from those reflected in the forward-looking statements due to a variety of risks, uncertainties and other factors, including, without limitation, those referred to in this AIF under the heading “Risk Factors”.

The Company’s forward-looking statements are based on the assumptions, beliefs, expectations and opinions of management on the date the statements are made, many of which may be difficult to predict and beyond the Company’s control. In connection with the forward-looking statements contained in this AIF, the Company has made certain assumptions about, among other things: favourable equity and debt capital markets; the ability to raise any necessary additional capital on reasonable terms to advance the production, development, construction and exploration of the Company’s properties and assets; future prices of copper, gold and other metal prices; the timing and results of exploration and drilling programs; the accuracy of any Mineral Reserve and Mineral Resource estimates; the geology of the Caraíba Operations, the Xavantina Operations and the Tucumã Operations being as described in the Caraíba Operations Technical Report, the Xavantina Operations Technical Report and the Tucumã Project Technical Report, respectively; production costs; the accuracy of budgeted exploration, development and construction costs and expenditures; the price of other commodities such as fuel; future currency exchange rates, interest rates and tariff rates; operating conditions being favourable such that the Company is able to operate in a safe, efficient and effective manner; work force continuing to remain healthy in the face of prevailing epidemics, pandemics or other health risks, political and regulatory stability; the receipt of governmental, regulatory and third party approvals, licenses and permits on favourable terms; obtaining required renewals for existing approvals, licenses and permits on favourable terms; requirements under applicable laws; sustained labour stability; stability in financial and capital goods markets; availability of equipment; positive relations with local groups and the Company’s ability to meet its obligations under its agreements with such groups; and satisfying the terms and conditions of the Company’s current loan arrangements. Although the Company believes that the assumptions inherent in forward-looking statements are reasonable as of the date of this AIF, these assumptions are subject to significant business, social, economic, political, regulatory, competitive and other risks and uncertainties, contingencies and other factors that could cause actual actions, events, conditions, results, performance or achievements to be materially different from those projected in the forward-looking statements. The Company cautions that the foregoing list of assumptions is not exhaustive. Other events or circumstances could cause actual results to differ materially from those estimated or projected and expressed in, or implied by, the forward-looking statements contained in this AIF.

Forward-looking statements contained herein are made as of the date of this AIF and the Company disclaims any obligation to update or revise any forward-looking statement, whether as a result of new information, future events or results or otherwise, except as and to the extent required by applicable securities laws.

Scientific and Technical Information

Except as set out below, scientific and technical information contained in this AIF relating to the Company’s mining operations located within the Curaçá Valley, northeastern Bahia State, Brazil (the “Caraíba Operations” and formerly known as the MCSA Mining Complex), is derived from, and in some instances is a direct extract from, and based on the assumptions, qualifications and procedures set out in, the report prepared in accordance with National Instrument 43-101, Standards of Disclosure for Mineral Projects (“NI 43-101”) and entitled “2022 Mineral Resources and Mineral Reserves of the Caraíba Operations, Curaçá Valley, Bahia, Brazil”, dated December 22, 2022 with an effective date of September 30, 2022, prepared by Porfirio Cabaleiro Rodriguez, FAIG, Bernardo Horta de Cerqueira Viana, FAIG, Fábio Valério Câmara Xavier, MAIG and Ednie Rafael Moreira de Carvalho Fernandes, MAIG all of GE21 Consultoria Mineral Ltda. (“GE21”), Dr. Beck Nader, FAIG of BNA Mining Solutions (“BNA”) and Alejandro Sepulveda, Registered Member (#0293) (Chilean Mining Commission) of NCL Ingeniería y Construcción SpA (“NCL”) (the “Caraíba Operations Technical Report”). Each of Porfirio Cabaleiro Rodriguez, FAIG, Bernardo Horta de Cerqueira Viana, FAIG, Fábio Valério Câmara Xavier, MAIG, Ednie Rafael Moreira de Carvalho Fernandes, MAIG, Dr. Beck Nader, FAIG and Alejandro Sepulveda, Registered Member (#0293) (Chilean Mining Commission), reviewed and approved the scientific and technical information relating to the Caraíba Operations contained in this AIF, other than under the heading “Caraíba Operations – Updated Information with respect to the Caraíba Operations”, and is a “qualified person” (“QP” or “Qualified Person”) and “independent” of the Company within the meanings of NI 43-101. Information of a scientific and technical nature in respect of the Caraíba Operations set out in the AIF under the heading “Caraíba Operations – Updated Information with respect to the Caraíba Operations”, has been reviewed and approved by Cid Gonçalves Monteiro Filho, SME RM (04317974), MAIG (No. 8444), FAusIMM (No. 329148) and Resource Manager of the Company. Mr. Gonçalves is a “qualified person” within the meanings of NI 43-101.

Except as set out below, scientific and technical information contained in this AIF relating to the Company’s mining operations located approximately 18 km west of the town of Nova Xavantina, southeastern Mato Grosso State, Brazil (the “Xavantina Operations” and formerly known as the “NX Gold Mine”), is derived from, and in some instances is a direct extract from, and based on the assumptions, qualifications and procedures set out in, the report prepared in accordance with NI 43-101 and entitled “Technical Report on the Xavantina Operations, Mato Grosso, Brazil”, dated May 12, 2023 with an effective date of October 31, 2022, prepared by Porfirio Cabaleiro Rodriguez, FAIG, Leonardo de Moraes Soares, MAIG and Guilherme Gomides Ferreira, MAIG, all of GE21 (the “Xavantina Operations Technical Report”). Each of Porfirio Cabaleiro Rodriguez, FAIG, Leonardo de Moraes Soares, MAIG and Guilherme Gomides Ferreira, MAIG, reviewed and approved the scientific and technical information relating to the Xavantina Operations contained in this AIF, other than under the heading “Xavantina Operations – Updated Information with respect to the Xavantina Operations”, and is a “qualified person” and “independent” of the Company within the meanings of NI 43-101. Information of a scientific and technical nature in respect of the Xavantina Operations set out in the AIF under the heading “Xavantina Operations – Updated Information with respect to the Xavantina Operations”, has been reviewed and approved by Cid Gonçalves Monteiro Filho, SME RM (04317974), MAIG (No. 8444), FAusIMM (No. 329148) and Resource Manager of the Company, who is a “qualified person” within the meanings of NI 43-101.

Except as set out below, scientific and technical information contained in this AIF relating to the Company’s mining operation, located within southeastern Pará State, Brazil (referred to herein as the “Tucumã Operations” or by its former name, the “Tucumã Project” or the “Boa Esperança Project”), is derived from, and in some instances is a direct extract from, and based on the assumptions, qualifications and procedures set out in, the report prepared in accordance with NI 43-101 and entitled “Boa Esperança Project NI 43-101 Technical Report on Feasibility Study Update”, dated November 12, 2021 with an effective date of August 31, 2021, prepared by Kevin Murray, P. Eng., Scott C. Elfen, P.E. (each of Ausenco Engineering Canada Inc.), Erin L. Patterson, P.E. (formerly employed by its affiliate Ausenco Engineering USA South Inc., and together with Ausenco Engineering Canada Inc., referred to as “Ausenco”), Carlos Guzmán, FAusIMM RM CMC of NCL and Emerson Ricardo Re, MSc, MBA, MAusIMM (CP) (No. 305892), Registered Member (No. 0138) (Chilean Mining Commission) and Resource Manager of the Company on the date of the report (now of HCM Consultoria

Geologica Eireli (“HCM”)) (the “Tucumã Project Technical Report”). Each of Kevin Murray, P. Eng., Erin L. Patterson, P.E., Scott C. Elfen, P.E., Carlos Guzmán, FAusIMM RM CMC and Emerson Ricardo Re, MAusIMM (CP), reviewed and approved the scientific and technical information relating to the Tucumã Project contained in this AIF, and is a “qualified person” of the Company within the meanings of NI 43-101 or, in the case of Erin L. Patterson, P.E., who is no longer employed by Ausenco, was a "qualified person" of the Company within the meanings of NI 43-101 on the date of the report. Each of Kevin Murray, P. Eng., Erin L. Patterson, P.E., Scott C. Elfen, P.E., and Carlos Guzmán, FAusIMM RM CMC is “independent” of the Company within the meanings of NI 43-101 or, in the case of Erin L. Patterson, P.E., was "independent" of the Company on the date of the report. Emerson Ricardo Re, MAusIMM (CP), as Resource Manager of the Company (on the date of the report and now of HCM), was not “independent” of the Company on the date of the report, within the meaning of NI 43-101. Information of a scientific and technical nature in respect of the Tucumã Operations set out in the AIF under the heading “Tucumã Operations – Updated Information with respect to the Tucumã Operations”, has been reviewed and approved by Cid Gonçalves Monteiro Filho, SME RM (04317974), MAIG (No. 8444), FAusIMM (No. 329148) and Resource Manager of the Company, who is a “qualified person” within the meanings of NI 43-101.

Reference should be made to the full text of the Caraíba Operations Technical Report, the Xavantina Operations Technical Report and the Tucumã Project Technical Report, each of which is available for review on the Company’s website at www.erocopper.com and under the Company’s profile on SEDAR+ at www.sedarplus.ca/landingpage/ and on EDGAR at www.sec.gov.

CIM Definition Standards

The Mineral Reserves and Mineral Resources for the Caraíba Operations (including as used in the Caraíba Operations Technical Report), the Xavantina Operations (including as used in the Xavantina Operations Technical Report), the Tucumã Operations (including as used in the Tucumã Project Technical Report) and the Furnas Project (including as used in the Furnas Project Technical Report) have been estimated in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) Definition Standards for Mineral Resources and Mineral Reserves adopted by the CIM Council on May 19, 2014 (the “CIM Standards” or “CIM Definition Standards”) and the CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines, adopted by CIM Council on November 29, 2019 (the “CIM Guidelines”), which are incorporated by reference in NI 43-101. The following definitions are reproduced from the CIM Definition Standards:

“Feasibility Study” means a comprehensive technical and economic study of the selected development option for a mineral project that includes appropriately detailed assessments of applicable Modifying Factors together with any other relevant operational factors and detailed financial analysis that are necessary to demonstrate, at the time of reporting, that extraction is reasonably justified (economically mineable). The results of the study may reasonably serve as the basis for a final decision by a proponent or financial institution to proceed with, or finance, the development of the project. The confidence level of the study will be higher than that of a Pre-Feasibility Study.

“Indicated Mineral Resource” means that part of a Mineral Resource for which quantity, grade or quality, densities, shape and physical characteristics are estimated with sufficient confidence to allow the application of Modifying Factors as described below in sufficient detail to support mine planning and evaluation of the economic viability of the deposit. Geological evidence is derived from adequately detailed and reliable exploration, sampling and testing and is sufficient to assume geological and grade or quality continuity between points of observation. An Indicated Mineral Resource has a lower level of confidence than that applying to a Measured Mineral Resource and may only be converted to a Probable Mineral Reserve.

“Inferred Mineral Resource” means that part of a Mineral Resource for which quantity and grade or quality are estimated on the basis of limited geological evidence and sampling. Geological evidence is sufficient to imply but not verify geological and grade or quality continuity. An Inferred Mineral Resource has a lower level of confidence than that applying to an Indicated Mineral Resource and must not be converted to a Mineral Reserve. It is reasonably expected that the majority of Inferred Mineral Resources could be upgraded to Indicated Mineral Resources with continued exploration.

“Measured Mineral Resource” means that part of a Mineral Resource for which quantity, grade or quality, densities, shape, and physical characteristics are estimated with confidence sufficient to allow the application of Modifying Factors to support detailed mine planning and final evaluation of the economic viability of the deposit. Geological evidence is derived from detailed and reliable exploration, sampling and testing and is sufficient to confirm geological and grade or quality continuity between points of observation. A Measured Mineral Resource has a higher level of confidence than that applying to either an Indicated Mineral Resource or an Inferred Mineral Resource. It may be converted to a Proven Mineral Reserve or to a Probable Mineral Reserve.

“Mineral Reserve” means the economically mineable part of a Measured and/or Indicated Mineral Resource. It includes diluting materials and allowances for losses, which may occur when the material is mined or extracted and is defined by studies at pre-feasibility or feasibility level as appropriate that include application of Modifying Factors. Such studies demonstrate that, at the time of reporting, extraction could reasonably be justified. The reference point at which Mineral Reserves are defined, usually the point where the ore is delivered to the processing plant, must be stated. It is important that, in all situations where the reference point is different, such as for a saleable product, a clarifying statement is included to ensure that the reader is fully informed as to what is being reported. The public disclosure of a Mineral Reserve must be demonstrated by a Pre-Feasibility Study or Feasibility Study.

“Mineral Resource” means a concentration or occurrence of solid material of economic interest in or on the Earth’s crust in such form, grade or quality and quantity that there are reasonable prospects for eventual economic extraction. The location, quantity, grade or quality, continuity and other geological characteristics of a Mineral Resource are known, estimated or interpreted from specific geological evidence and knowledge, including sampling.

“Pre-Feasibility Study” means a comprehensive study of a range of options for the technical and economic viability of a mineral project that has advanced to a stage where a preferred mining method, in the case of underground mining, or the pit configuration, in the case of an open pit, is established and an effective method of mineral processing is determined. It includes a financial analysis based on reasonable assumptions on the Modifying Factors and the evaluation of any other relevant factors which are sufficient for a qualified person, acting reasonably, to determine if all or part of the Mineral Resource may be converted to a Mineral Reserve at the time of reporting. A Pre-Feasibility Study is at a lower confidence level than a Feasibility Study.

“Probable Mineral Reserve” means the economically mineable part of an Indicated, and in some circumstances, a Measured Mineral Resource. The confidence in the Modifying Factors applying to a Probable Mineral Reserve is lower than that applying to a Proven Mineral Reserve.

“Proven Mineral Reserve” means the economically mineable part of a Measured Mineral Resource. A Proven Mineral Reserve implies a high degree of confidence in the Modifying Factors.

For the purposes of the CIM Definition Standards, “Modifying Factors” are considerations used to convert Mineral Resources to Mineral Reserves. These include, but are not restricted to, mining, processing, metallurgical, infrastructure, economic, marketing, legal, environmental, social and governmental factors.

Cautionary Notes Regarding Mineral Resource and Mineral Reserve Estimates

Unless otherwise indicated, all reserve and resource estimates included in this AIF and the documents incorporated by reference herein have been prepared in accordance with NI 43-101 and the CIM Standards. NI 43-101 is a rule developed by the Canadian Securities Administrators that establishes standards for all public disclosure an issuer makes of scientific and technical information concerning mineral projects. Canadian standards, including NI 43-101, differ significantly from the requirements of the United States Securities and Exchange Commission (the “SEC”), and reserve and resource information included herein may not be comparable to similar information disclosed by U.S. companies. In particular, and without limiting the generality of the foregoing, this AIF and the documents incorporated by reference herein use the terms “measured resources,” “indicated resources” and “inferred resources” as defined in accordance with NI 43-101 and the CIM Standards.

Further to recent amendments, mineral property disclosure requirements in the United States (the “U.S. Rules”) are governed by subpart 1300 of Regulation S-K of the U.S. Securities Act of 1933, as amended (the “U.S. Securities Act”) which differ from the CIM Standards. As a foreign private issuer that is eligible to file reports with the SEC pursuant to the multi-jurisdictional disclosure system (the “MJDS”), Ero is not required to provide disclosure on its mineral properties under the U.S. Rules and will continue to provide disclosure under NI 43-101 and the CIM Standards. If Ero ceases to be a foreign private issuer or loses its eligibility to file its annual report on Form 40-F pursuant to the MJDS, then Ero will be subject to the U.S. Rules, which differ from the requirements of NI 43-101 and the CIM Standards.

Pursuant to the new U.S. Rules, the SEC recognizes estimates of “measured mineral resources”, “indicated mineral resources” and “inferred mineral resources”. In addition, the definitions of “proven mineral reserves” and “probable mineral reserves” under the U.S. Rules are now “substantially similar” to the corresponding standards under NI 43-101. Mineralization described using these terms has a greater amount of uncertainty as to its existence and feasibility than mineralization that has been characterized as reserves. Accordingly, U.S. investors are cautioned not to assume that any measured mineral resources, indicated mineral resources, or inferred mineral resources that Ero reports are or will be economically or legally mineable. Further, “inferred mineral resources” have a greater amount of uncertainty as to their existence and as to whether they can be mined legally or economically. Under Canadian securities laws, estimates of “inferred mineral resources” may not form the basis of feasibility or pre-feasibility studies, except in rare cases. While the above terms under the U.S. Rules are “substantially similar” to the standards under NI 43-101 and CIM Standards, there are differences in the definitions under the U.S. Rules and CIM Standards. Accordingly, there is no assurance any mineral reserves or mineral resources that Ero may report as “proven mineral reserves”, “probable mineral reserves”, “measured mineral resources”, “indicated mineral resources” and “inferred mineral resources” under NI 43-101 would be the same had Ero prepared the reserve or resource estimates under the standards adopted under the U.S. Rules.

Alternative Performance (Non-IFRS) Measures

Financial results of the Company are prepared in accordance with the International Financial Reporting Standards (“IFRS”). The Company utilizes certain performance measures to monitor its performance, including copper C1 cash cost, copper C1 cash cost including foreign exchange hedges, realized copper price, gold C1 cash cost, gold all-in sustaining cost (“AISC”), realized gold price, earnings before interest, taxes, depreciation and amortization (“EBITDA”), adjusted EBITDA, adjusted net income attributable to owners of the Company, adjusted net income per share, net (cash) debt, working capital and available liquidity. These performance measures have no standardized meaning prescribed within generally accepted accounting principles under IFRS and, therefore, amounts presented may not be comparable to similar measures presented by other mining companies. These non-IFRS measures are intended to provide supplemental information and should not be considered in isolation or as a substitute for measures of performance prepared in accordance with IFRS. The reader is directed to the Management’s Discussion and Analysis of the Company for the year ended December 31, 2024 (see “Alternative Performance (Non-IFRS) Measures” section) for a reconciliation of these non-IFRS measures to the most directly comparable IFRS measures as contained in the Company’s audited consolidated financial statements for the years ended December 31, 2024 and 2023. Unless otherwise noted, the non-IFRS measures presented herein have been calculated on a consistent basis for the periods presented.

Copper C1 Cash Cost and Copper C1 Cash Cost including Foreign Exchange Hedges

Copper C1 cash cost and copper C1 cash cost including foreign exchange hedges are non-IFRS performance measures used by the Company to manage and evaluate the performance of its copper mining operations.

Copper C1 cash cost is calculated as C1 cash costs divided by total pounds of copper produced during the period. C1 cash costs comprise the total cost of production, including expenses related to transportation, and treatment and refining charges. These costs are net of by-product credits, incentive payments and certain tax credits associated with sales invoiced to the Company's Brazilian customer.

Copper C1 cash cost including foreign exchange hedges is calculated as C1 cash costs, adjusted for realized gains or losses from its operational foreign exchange hedges, divided by total pounds of copper produced during the period. Although the Company does not apply hedge accounting in its consolidated financial statements and recognizes these contracts at fair value through profit or loss, the Company believes it appropriate to present cash costs including the impact of realized gains and losses as these contracts were entered into to mitigate the impact of changes in exchange rates.

While copper C1 cash cost is widely reported in the mining industry as a performance benchmark, it does not have a standardized meaning and is disclosed as a supplement to IFRS measures.

Realized Copper Price

Realized copper price is a non-IFRS ratio which is calculated as gross copper revenue divided by pounds of copper sold during the period. Management believes measuring realized copper price enables investors to better understand performance based on realized copper sales in each reporting period.

Gold C1 Cash Cost

Gold C1 cash cost is a non-IFRS performance measure used by the Company to manage and evaluate the operating performance of its gold mining segment and is calculated as C1 cash costs divided by total ounces of gold produced during the period. C1 cash cost includes total cost of production, net of by-product credits and incentive payments. Gold C1 cash cost is widely reported in the mining industry as benchmarks for performance but does not have a standardized meaning and is disclosed in supplemental to IFRS measures.

Gold AISC

Gold AISC is an extension of gold C1 cash cost discussed above and is also a key performance measure used by management to evaluate operating performance of its gold mining segment. Gold AISC is calculated as AISC divided by total ounces of gold produced during the period. AISC includes C1 cash costs, site general and administrative costs, accretion of mine closure and rehabilitation provision, sustaining capital expenditures, sustaining leases, and royalties and production taxes. Gold AISC is widely reported in the mining industry as benchmarks for performance but does not have a standardized meaning and is disclosed in supplement to IFRS measures.

Realized Gold Price

Realized gold price is a non-IFRS ratio that is calculated as gross gold revenue divided by ounces of gold sold during the period. Management believes measuring realized gold price enables investors to better understand performance based on the realized gold sales in each reporting period.

EBITDA and Adjusted EBITDA

EBITDA and adjusted EBITDA are non-IFRS performance measures used by management to evaluate its debt service capacity and performance of its operations. EBITDA represents earnings before finance expense, finance income, income taxes, depreciation and amortization. Adjusted EBITDA is EBITDA before the pre-tax effect of adjustments for non-cash and/or non-recurring items required in determination of EBITDA for covenant calculation purposes.

Adjusted net income attributable to owners of the Company and Adjusted net income per share attributable to owners of the Company

“Adjusted net income attributable to owners of the Company” is net income attributed to shareholders as reported, adjusted for certain types of transactions that, in management's judgment, are not indicative of our normal operating activities or do not necessarily occur on a recurring basis. “Adjusted net income per share attributable to owners of the Company” (“Adjusted EPS”) is calculated as "adjusted net income attributable to owners of the Company" divided by weighted average number of outstanding common shares in the period.

The Company believes that, in addition to conventional measures prepared in accordance with IFRS, the Company and certain investor and analysts use these supplemental non-IFRS performance measures to evaluate the normalized performance of the Company. The presentation of Adjusted EPS is not meant to substitute the net income (loss) per share attributable to owners of the Company (“EPS”) presented in accordance with IFRS, but rather it should be evaluated in conjunction with such IFRS measures.

Net (Cash) Debt

Net debt is a performance measure used by the Company to assess its financial position and ability to pay down its debt. Net debt is determined based on cash and cash equivalents, short-term investments, net of loans and borrowings as reported in the Company’s consolidated financial statements.

Working Capital (Deficit) and Available Liquidity

Working capital is calculated as current assets less current liabilities as reported in the Company’s consolidated financial statements. The Company uses working capital as a measure of the Company’s short-term financial health and ability to meet its current obligations using its current assets. Available liquidity is calculated as the sum of cash and cash equivalents, short-term investments and the undrawn amount available on its revolving credit facilities. The Company uses this information to evaluate the liquid assets available.

For further details on Non-IFRS measures, please refer to the Company’s annual audited consolidated financial statements for the year ended December 31, 2024 and Management’s Discussion and Analysis relating thereto, a copy of which is available for review under the Company’s profile on SEDAR+ atwww.sedarplus.ca/landingpage/ and EDGAR at www.sec.gov.