Two new tellurite-phosphates NaTePO₅, SrTeP₂O₈ and the previously reported Ba₂TeP₂O₉ were synthesized successfully via high-temperature solid-state reactions and their structures were determined by single-crystal X-ray diffraction. The structures of NaTePO₅ and SrTeP₂O₈ feature two-dimensional (2D) [TePO₅]^- and [TeP₂O₈]^2- anionic layers interleaved with Na⁺ and Sr²⁺ cations, respectively. The ³¹P NMR spectra show that electron density around phosphorus atoms in SrTeP₂O₈ is slightly larger than that in Ba₂TeP₂O₉, owing to the connection modes of [TeO₅] and [PO₄] units and counter-ion effects. The calculated electric field strength (Z/a²) based on the ³¹P chemical shift indicate as the chemical shift increases the Z/a² also increases, as evidenced by the binding energy of P 2p determined by the X-ray photoelectron spectroscopy. Further, first-principle calculations show that the NaTePO₅, SrTeP₂O₈ and Ba₂TeP₂O₉ exhibit large birefringence of 0.212, 0.133 and 0.126 at 1064 nm, respectively, compared to other phosphates.