If you have given a former tenant permission (licence) to assign their lease and the current tenant failed to pay the rent due on 24 June, you may able to recover the rent arrears from the former tenant or their guarantor if you obtained an Authorised Guarantee Agreement (AGA) as part of the licence to assign. ACT NOW as you need to serve a formal notice on that former tenant / guarantor and the expiry date for that notice is usually 23 December 2020, depending upon the terms of the lease. This recovery is not affected by the Government restrictions on recover of rent arrears due to Covid-19. The notice does not itself initiate the rent recovery process, but without the notice, you will not be able to use this route for the June 2020 quarter rent arrears.