Why the question is worth asking directly
Undisclosed subcontracting breaks the chain a contractor file is meant to establish. The insurance certificate covers one entity while another performs the work. The screening confirmation describes one group of workers while different people attend. The induction record names individuals nobody has seen. None of that is visible from the outside, and it usually surfaces only when something goes wrong.
It also affects continuity. A client who thinks they have a direct arrangement may find that a change of subcontractor replaces the entire team without notice, taking the site knowledge with it. Asking at quoting stage costs nothing and the answer is informative either way. A contractor who is straightforward about the arrangement is easier to work with than one who is technically accurate but evasive.
