The function of SLC34A3 (solute carrier family 34 member 3, ENSG00000198569) is as follows. Involved in actively transporting phosphate into cells via Na(+) cotransport in the renal brush border membrane (PubMed:11880379). The cotransport has a Na(+):Pi stoichiometry of 2:1 and is electroneutral (By similarity). {ECO:0000250|UniProtKB:Q80SU6, ECO:0000269|PubMed:11880379}.