The crystal structure of oxido-nitro-gen(1+) tetra-fluorido-borate (nitro-sonium tetra-fluorido-borate), NO + BF 4 - , was refined on the basis of single-crystal X-ray diffraction data at 150 K. The compound crystallizes in the baryte structure type with ortho-rhom-bic Pnma symmetry. The crystal structure exhibits cationic disorder with equal occupation of N and O atoms at the same site.