Just to illustrate, picture this scenario:
My client is the CEO of a company. A request has been made by his/her secretary, I still need to save his/her details to keep track of the service.
What would you call the secretary on this scenario? I'm aware the word "requestor" is not really used by native speakers, so how'd one call this person in a "not very long" way? (e.g. "person who has booked the service")
ps: i could use "Requested by:" but later i have to collect their contact info such as phone and email.