<p>We consider the nonlocal Cahn–Hilliard equation endowed with source terms modeling phase transition of a two-phase mixture under nonlocal interactions. For the associated initial-boundary value problem in a bounded domain, we first introduce two notions of weak solution. The first one, called “generalized” weak solution, is based on the splitting of the chemical potential so that the entropy derivative does not need to be integrable. The second is slightly stronger and allows to reconstruct the chemical potential itself and establish a canonical energy identity. The relation between these two notions of weak solution is also analyzed. We then prove our first main result, namely the uniqueness of generalized weak solutions as well as a continuous dependence estimate under general assumptions on the sources. The presence of the source term in the Cahn–Hilliard equation makes the proof quite delicate, since in this case, mass is not conserved. We then prove the second main result, which consists in the strict and instantaneous separation property. This means that every generalized weak solution, from an arbitrarily short time on, remains separated from the pure phases. This property was established in (J. Math. Anal. Appl. 2011) for the nonlocal model without sources. Here, under minimal assumptions on the sources, we recover the strict separation property for the nonlocal Cahn–Hilliard equation including sources. Moreover, the result is achieved by means of a fully rigorous proof.</p>