The taxman always wants to be paid and as they make the law they can go after the easiest target. In this case the money is with the tenant/agent so that's who

The taxman always wants to be paid and as they make the law they can go after the easiest target. In this case the money is with the tenant/agent so that's who they go after. Of course the landlord would then owe the money to the tenant if the tenant had to pay out of their own pocket. I also expect that a non resident landlord would usually use an agent, in which case the tenant should be 'safe'.