This paper is focused on the existence of a torus that is invariant with respect to the flow of a presymplectic vector field in an exact presymplectic manifold. The result is stated in an “a posteriori” form, meaning that if there exists an embedding that is an approximately invariant torus, then under the Diophantine condition on the frequency and some nondegenerate condition on the parameter and on the initial embedding torus, the invariant torus exists in the sense of embedding, provided the initial error function is sufficiently small. Moreover, the true invariant torus and the approximated invariant torus are very close to each other. An advantage of this method is its suitability for validation of numerical results since it does not require action-angle variables.