  We aim to characterize the magnetospheric accretion process in the young
stellar object V807 Tau, one of the most stable dippers revealed by K2 in the
Taurus star forming region. We performed photometric and spectropolarimetric
follow-up observations of this system with CFHT/ESPaDOnS in order to
investigate its variability over several rotational periods. We derive a 4.38
day period from the K2 light curve. This period is also seen in the radial
velocity variations, ascribed to spot modulation. The narrow component of the
He I 5876 {\AA} line as well as the red wing of the H{\beta} and H{\gamma} line
profiles also vary in intensity with the same periodicity. The former traces
the accretion shock at the stellar surface, and the latter is a signature of an
accretion funnel flow crossing the line of sight. We derive a surface
brightness and magnetic field topology from the modeling of Stokes I and V
profiles, respectively, for photospheric lines and for the He I line. This
reveals a bright spot at the stellar surface, located at a latitude of 60 deg,
and a maximum field strength of about 2 kG. The magnetic field topology at the
stellar surface is dominated by a dipolar component inclined by about 40 deg
onto the spin axis. Despite of its clear and stable dipper behavior, we derive
a relatively low inclination of about 50 deg for this system, which calls
question the origin of the dips. This low inclination is also consistent with
the absence of deep inverse P Cygni components in the line profiles. We
conclude that magnetospheric accretion is ongoing in V807 Tau, taking place
through non-axisymmetric accretion funnel flows controlled by a strong, tilted,
and mainly dipolar magnetic topology. Whether an inner disk warp resulting from
this process can account for the dipper character of this source remains to be
seen, given the low inclination of the system.
