on someone's behalf

Advocacy: Acting on Someone’s Behalf
Advocacy: Speaking on Someone’s Behalf
handling someone's tax affairs, managing tax on someone else's behalf, authorised agent, tax agent, tax representative, manage tax a...
Authentication of a digital voice conversation
Finlay on Legitimate Authority: A Critical Comment
Seven Times When it's OK to Check Someone's Credit Report
Ombuds' Corner: letter from Ombudsland
Keys/Access Cards, Deakin University
Someone's Got to Give; for True Peace, the Haves of the World Must Be Willing to Share
MedEconomics: Complaints on patients' behalf