on one's say-so

According to one's authority, as in I'm reorganizing the files on the boss's say-so, or You can skip the exam? On whose say-so? The noun say-so, dating from about 1630, originally meant simply “saying something,” that is, an assertion (without authority or proof). By the early 1800s it had acquired its present meaning.

Words nearby on one's say-so

on one's mind, on one's own, on one's own account, on one's own time, on one's part, on one's say-so, on one's shoulders, on one's soapbox, on one's tail, on one's toes, on one's uppers