  Recently \cite{Horowitz:2022rpp,Horowitz:2022uak}, denominator regularisation
(Den. Reg.) scheme has been proposed to handle divergences in quantum field
theory. It is shown to yield results as simple as in dimensional regularisation
scheme and also shown to be compatible with minimal subtraction scheme by
taking several examples in field theory. In this article, we point out some
interesting features of this regularisation scheme which appear as a
consequence of the requirement of gauge invariance by revisiting QED vacuum
polarisation and $H\to\gamma\gamma$ decay in this regularisation scheme.
