Commercially viable synthesis of InP nanocrystals (NCs) involves highly pyrophoric phosphorus (P) precursor, tris(trimethylsilyl) phosphine (TMS3P). Finding a cheap and safe alternative would be the holy grail. We report the synthesis of InP NCs using triphenyl phosphite, an inexpensive and relatively safe phosphorous source. By reacting indium chloride and triphenyl phosphite, we obtained large-sized and black-colored InP NCs, yet without any distinct feature that shows quantum confinement effect. Addition of ZnCl2 resulted in InP NCs with controlled size, which was manifested in the shift of 1S peak in absorption spectra. By coating ZnS shell on InP NCs, we achieved photoluminescence with some extent of trap emission, showing maximum total quantum yield (QY) of 23% (8% of band-edge emission QY). We used 31P nuclear magnetic resonance (NMR), diffusion-ordered spectroscopy (DOSY), and mass spectrometry (MS) to assign intermediates and following mechanisms of the InP synthesis using triphenyl phosphite. The development of this safe and cost-effective P precursor opens broader opportunity space for large-scale production of InP NC.