Right to rent
Under the right to rent legislation it falls on the person granting permission to occupy to comply with the provisions, including carrying out the appropriate checks and copying ID and other documents. The agreement between the landlord owner and the rent to renter should make it clear that it is the rent to renter who is responsible for these checks.
In other jurisdictions there may be additional requirements and complications. For example, in Wales landlords need to be registered and obtain a licence to self-manage. In the case of rent to rent it is not the landlord owner who needs to be registered but the immediate residential landlord, the rent to renter, who will also need a licence to manage. Again, this should be stipulated in the rent to rent agreement when letting in Wales.