Acts as a sodium-independent DIDS-sensitive anion exchanger mediating bicarbonate, chloride, sulfate and oxalate transport. May play a role in the maintenance of the electrolyte and acid-base homeostasis in the kidney, by acting as a distal excretory segment-specific anion exchanger, specifically chloride. Plays a major role in gastric acid secretion. Expressed on the basolateral membrane of acid-secreting gastric parietal cells, distal nephron segments and apical domains of proximal tubules and in the glomerulus. Expressed in the cytoplasm in recycling endosomes of kidney outer medullary collecting duct cells and in acid-secreting gastric parietal cells. Targeted to the basolateral membrane in hypertonicity and potassium depletion. Abundantly expressed in parietal cells on the glandular portion of the stomach. Lower levels are observed in the kidney, with expression in the proximal tubule and thick ascending limb of the loop of Henle. Also expressed in distal segments of nephron, in extraglomerular mesagial cells and a subpopulation of intercalated cells of outer medullary collecting ducts. Regulated by pH. Activity inhibited by all inhibitors of several anion channels and transporters, including 4,4'-Di-isothiocyanatostilbene-2,2'-disulfonic acid (DIDS), diphenylamine-2-carboxylic acid and glybenclamide. Belongs to the SLC26A/SulP transporter (TC 2.A.53) family.