Formulation of theories with local symmetries in presence of boundaries has revealed interesting features, stressing further the significance of "boundary degrees of freedom" (b.d.o.f.) and the symmetries and algebras arranging the b.d.o.f. In particular, one may apply these ideas to black hole solutions to gravity theories where the horizon can be viewed as a null boundary for the set of observers outside the horizon. The b.d.o.f. and the associated charges and algebras in these examples may remedy problem of identification of black hole microstates. In this talk I provide a general discussion on the null boundary symmetries and algebras and summarise and the latest developments in realisation of the Hawking-Perry-Strominger idea.