The questioner noted that:
CRA has in [the context of Reg. 400(2)(b)] ascribed an ordinary meaning to the word "agent", [as] being one who is authorized to act for or in place of another. This view of the meaning of the word "agent" is sufficiently broad that a public warehouse that acts only to store and ship goods for a particular corporation would typically be deemed to be a permanent establishment of that corporation for provincial income allocation purposes.
In response, CRA noted the statement in Canada v. Merchant Law Group, 2010 FCA 206 that "it is settled at common law that for an agency relationship to exist the agent must be able to affect the principal's legal position with third parties by entering into contracts on the principal's behalf or by disposing of the principal's property," and then stated:
We are of the opinion that sufficient support exists for using the legal meaning of the word "agent" in situations involving allocation for provincial income tax purposes and the CRA is prepared to change its position on a prospective basis.