Enables chloride:bicarbonate antiporter activity. Acts upstream of or within monoatomic anion transport. Located in apical plasma membrane and basolateral plasma membrane. Is expressed in several structures, including cardiovascular system; immature eye; midbrain neural rod; optic tectum; and pronephric duct. Human ortholog(s) of this gene implicated in osteopetrosis. Orthologous to human SLC4A2 (solute carrier family 4 member 2).