  Various equivalences between so-called soft theorems which constrain
scattering amplitudes and Ward identities related to asymptotic symmetries have
recently been established in gauge theories and gravity. So far these
equivalences have been restricted to the case of massless matter fields, the
reason being that the asymptotic symmetries are defined at null infinity. The
restriction is however unnatural from the perspective of soft theorems which
are insensitive to the masses of the external particles.
  In this work we remove the aforementioned restriction in the context of
scalar QED. Inspired by the radiative phase space description of massless
fields at null infinity, we introduce a manifold description of time-like
infinity on which the asymptotic phase space for massive fields can be defined.
The "angle dependent" large gauge transformations are shown to have a well
defined action on this phase space, and the resulting Ward identities are found
to be equivalent to Weinberg's soft photon theorem.
