• от имени и по поручению – on behalf of and upon the instructions of
• от имени и по поручению – on behalf of and on the instructions of
• от имени и по поручению – for and on behalf of
• благодарить от имени – thank on behalf of
• выступать от имени – speak on behalf of
См. также: от берега, от лица, от судьбы не уйдёшь, от такого-то числа такого-то месяца
In everyday use "in the name of" is taken to mean that you are invoking the full authority of someone or something else such as an official, or the law, or even of God but "on behalf of" is taken to mean that you are acting as an agent of someone else with only limited or conditional authority. (EnglishForward)
As members of the union, we have the right to know what action the union is taking in our name. (Cambridge Advanced Learner's Dictionary & Thesaurus)
