Global magnetic field topology of τ Sco derived with ZDI inversions for the case of a) direct parameterisation of the magnetic maps (Model 1) and b) harmonic parameterisation with β_ℓ,m ≠ α_ℓ,m,γ_ℓ,m ≠ 0 (Model 2). In each panel the left column shows the flattened polar projection of the radial, meridional, and azimuthal field components. The colour bar indicates the field strength in kG. The observed (thin black line) and computed (thick red line) LSD Stokes V profiles are compared on the right side of each panel. The profiles are offset vertically according to the rotational phase indicated next to each spectrum.