In behalf, they argue, is used when the meaning is in the interest of someone else, but on behalf is used when speaking for someone. For example, a medical decision would be made in behalf of the patient, and you would speak on behalf of your family.

Is it our behalf or Behalves?

A: In modern usage, “behalf” is an invariable noun and has no plural form. The old plural “behalves” is considered obsolete and has been for some time.

What is the meaning of Behalves?

: interest, benefit also : support, defense argued in his behalf. on behalf of or in behalf of. : in the interest of also : as a representative of I wrote the letter on behalf of my client. On Behalf of vs.