Ero Copper Corp.

(iii)Development and construction-in-progress

When economically viable mineral reserves have been determined and the decision to proceed with development has been approved, exploration and evaluation assets are first assessed for impairment, then reclassified to construction-in-progress or mineral properties. The expenditures related to development and construction are capitalized as construction-in-progress. Borrowing costs directly attributable to the acquisition, construction or production of a qualifying asset that takes a substantial period of time to get ready for its intended use are capitalized as part of construction-in-progress until the asset is substantially ready for its intended use. Construction-in-progress is not depreciated.

Once an asset is available for use, construction-in-progress costs are reclassified to mineral properties or plant and equipment.

Pre-production costs of removing overburden to access ore in the open pit mines and developing access headings in the underground mines are capitalized as pre-production stripping or development costs respectively and are included within mineral properties, plant and equipment.