We study the time reversal and space inversion symmetry properties of the transfer matrices mostly used in the calculation of energy spectra and transport-process quantities. We determine the unitary transformation relating transfer matrices. We consider the Kohn-Luttinger model for a quasi-2D system and show that even though the system studied in the (4 × 4) scheme satisfies all the symmetry requirements, the (2 × 2) subspaces do not fulfill such constrains, except in the point of the Brillouin Zone. We find new exchange properties between the (2 × 2) subspace quantities.