“principal” means a person on whose behalf an agent carries on the business of supply or receipt of goods or services or both;
The law uses the term ‘principal’ in the context of two relationships – one in case of the principal and job worker, and the other in case of principal and agent. However, in the provisions relating to job work, the term has a separate meaning, the reference of which is separately provided for. Therefore, one must understand the meaning of the term ‘principal’ wherever else the term finds a mention, as a reference to the principal-agent relationship.
Agent of the principal is one who carries on the business of supply or receipt of goods or services or both on behalf of another person, being the principal. The agent functions as an extended arm of the principal and therefore, supplies (inward and outward) effected by an agent on behalf of the principal will be treated as supplies effected by the principal.
Note the remarkable resemblance to the reference in parallel to paragraph 3, schedule I.