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). 2 Na(+)(out) + phosphate(out) = 2 Na(+)(in) + phosphate(in) Optimum pH is 7.5. ocalized at the brush border membrane in the kidney. Expressed only in the kidney. The disease is caused by variants affecting the gene represented in this entry. Belongs to the SLC34A transporter family.