For standalone Rent Protection policies, a credit check on the tenant must be carried out from a licensed credit referencing company before the policy starts.
Credit reference companies give lenders a range of information about potential borrowers, which lenders use to make decisions about whether they will offer you credit or not.
See list of approved tenant referencing providers on Arcs website here: https://claims.arclegal.co.uk/info/approved-tenant-referencing-providers