Difference between Sub-Agent and Substituted-Agent

No	Sub-Agent	Substituted-Agent
1	Definition :           According to Section 191 of the Indian Contract Act, 1872 - A “sub-agent” is a person employed by, and acting undue the control of, the original agent in the business of the agency.	Definition :        A Substituted agent is a person who is named by the Agent for performing such part of the business of the agency as is entrusted to him.
2	Sub-Agent works under the control of the Agent. He is the agent of the Principle.	Substituted Agent works under the control of the Principle and he is an agent of the agent.
3	Sub-Agent is responsible to the Agent.	Substituted Agent is responsible to the principal
4	The Agent is responsible for the acts of the sub-agent.	The agent is not responsible for the acts of the substituted-agent
5	There is no Privity of contract between the Principle and sub-agent.	There is privity of Contract between the Principal and substituted-agent.

See also 

1)  Difference / Distinction between Contract and Agreement

2) Difference/ Distinction between Coercion and Undue Influence

3) Difference /Distinction between Void and Voidable Contracts

4) Difference / Distinction Between Condition and Warranty

5)  Revocation of continuing guarantee by change in firm