  We undertook a time-series photometric multi-site campaign for the rapidly
oscillating Ap star HD 99563 and also acquired mean light observations over two
seasons. The pulsations of the star, that show flatter light maxima than
minima, can be described with a frequency quintuplet centred on 1557.653
microHertz and some first harmonics of these. The amplitude of the pulsation is
modulated with the rotation period of the star that we determine with 2.91179
+/- 0.00007 d from the analysis of the stellar pulsation spectrum and of the
mean light data. We break the distorted oscillation mode up into its pure
spherical harmonic components and find it is dominated by the l=1 pulsation,
and also has a notable l=3 contribution, with weak l=0 and 2 components. The
geometrical configuration of the star allows one to see both pulsation poles
for about the same amount of time; HD 99563 is only the fourth roAp star for
which both pulsation poles are seen and only the third where the distortion of
the pulsation modes was modelled. We point out that HD 99563 is very similar to
the well-studied roAp star HR 3831. Finally, we note that the visual companion
of HD 99563 is located in the Delta Scuti instability strip and may thus show
pulsation. We show that if the companion was physical, the roAp star would be a
2.03 solar mass object, seen at a rotational inclination of 44 degrees, which
then predicts a magnetic obliquity of 86.4 degrees.
