Using the solution of the problem of light scattering by a homogeneous spheroid, derived by separation of variables in spheroidal coordinates, we find the 'spheroidal' T-matrix. We suggest a transformation of this matrix into the 'spherical' T-matrix useful in applications. The procedure consists of two steps: first, transition from spheroidal to spherical basis, and then from spherical non-orthogonal to orthogonal basis.