Involved in actively transporting phosphate into cells via Na(+) cotransport in the renal brush border membrane (PubMed:26047794, PubMed:8327470, PubMed:12324554, PubMed:20335586). The cotransport has a Na(+):Pi stoichiometry of 3:1 and is electrogenic (By similarity). 3 Na(+)(out) + phosphate(out) = 3 Na(+)(in) + phosphate(in) Optimum pH is 8.0. Interacts via its C-terminal region with PDZK2 (By similarity). Interacts with SLC9A3R1 (PubMed:22506049). Localized at the brush border membranes of the proximal tubules. Kidney and lung. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the SLC34A transporter family.