Phosphatase that has high activity toward pyridoxal 5'-phosphate (PLP). Also active at much lower level toward pyrophosphate, phosphoethanolamine (PEA), phosphocholine (PCho), phospho-l-tyrosine, fructose-6-phosphate, p-nitrophenyl phosphate, and h-glycerophosphate. H2O + pyridoxal 5'-phosphate = phosphate + pyridoxal Belongs to the HAD-like hydrolase superfamily. PHOSPHO family.