An agent without authority cannot lawfully appoint a sub-agent EXCEPT:

1. Section 190 — an agent may delegate or appoint a sub-agent only if authorised by the principal expressly or impliedly, OR by the ordinary custom of trade. 2. Unauthorised delegation does not bind the principal. 3. Hence (A). _Source: ICAI BoS CA Inter Paper 2 — Indian Contract Act 1872_