A detailed study of sum rules for E0, E2 and M1 and M3 transitions within the framework of the proton-neutron interacting boson model (IBM-2) is carried out. Both the non-energy-weighted as well as linear energy-weighted sum rules are derived for rather general IBM-P Hamiltonians. Special attention is given to the M1 sum rule for which a large amount of data exists. We also show how these more general sum rule results reduce to simple answers when considering the limit of U(5), SU(3), and O(6) dynamical symmetries. Finally, a relation between the MI and M3 sum rules is pointed out.