その依頼人は常に正しいです。

English Translation

The client is always right.

What’s the proper pronunciation of 依頼人 because I’m seeing three different ones:
いらいにん, いらいひと, or いらいじん? I’m assuming it’s the first one, but I wanted to be sure.

@TisYanni
いらいにん is the only correct pronunciation. The same pattern can be applied to:

  • 被告人 (ひこくにん) : defendant (in legal court)
  • 調査人 (ちょうさにん) : inspector
  • 差出人 (さしだしにん) : sender of packages, letters, email, etc.
  • 受取人 (うけとりにん) : addressee of packages, letters, email, etc.
  • 穢多・非人 (えた・ひにん) : the lowest social class in the Edo era

I cannot generalize all cases, but ~にん is frequently used for social roles.

~じん is often used in the context of nationality, ethnicity or race but not limited to these demographic terms:

  • アメリカ人 (アメリカじん) : Americans
  • 白人 (はくじん) : Caucasian
  • ユダヤ人 (ユダヤじん) : Jews
  • 渡来人 (とらいじん) : Immigrants from China or Korea to Japan around 4-7 centuries
  • 巨人 (きょじん) : Giants or Goliath (literally means “super big person”)
  • 偉人 (いじん) : Heroes or honorable persons with great achievements
  • 教養人 (きょうようじん) : Well-educated persons

巨人, 偉人 and 教養人 are interchangeable with すごく大きい人, 偉い人 and 教養のある人. So ~じん is sometimes used when it is preceded by a (quasi-) adjective.

~ひと (hito) is hardly used as a compound word and ~びと (bito) sounds phonetically more natural. I cannot come up with examples for this pronunciation.