  We introduce Ward identities for superamplitudes in D-dimensional N-extended
supergravities. These identities help to clarify the relation between
linearized superinvariants and superamplitudes. The solutions of these Ward
identities for an $n$-partice superamplitude take a simple universal form for
half-BPS and non-BPS amplitudes. These solutions involve arbitrary functions of
spinor helicity and Grassmann variables for each of the $n$ superparticles. The
dimension of these functions at a given loop order is exactly the same as the
dimension of the relevant superspace Lagrangians depending on half-BPS or
non-BPS superfields, given by $(D-2) L +2- N$ or $(D-2) L +2- 2 N$,
respectively. This explains why soft limits predictions from superamplitudes
and from superspace linearized superinvariants agree.
