Bicarbonate transporters that move BICARBONATE ions in exchange of CHLORIDE ions or sodium ions across membranes. They regulate acid-base homeostasis, cell volume and intracellular pH. Members include chloride-bicarbonate antiporters (SLC4A1, 2, 3, and 9); sodium-COUPLED BICARBONATE TRANSPORTERS (SLC4A4 and 5, 7, 8 and 10); and a sodium borate cotransporter (SLC4A11 protein).