Is 建て【だて】 ever obligatory after a currency?


I have only come across 建て【だて】 rarely, such as in the following sentence:

給料【きゅうりょう】はルーブル建【だ】てなので、もう紙切【かみきれ】れです

_My salary is in rubles, so it's just scrap paper now._

<https://www.asahi.com/articles/ASQ3B7J6JQ3BULFA028.html?iref=comtop_ThemeLeftS_02>

Are there times when one must use 建て【だて】, or can it be omitted?




It depends on the construction. 給料はルーブルです is fine in casual speech, but when
written in business context, it may look slightly sloppy (only slightly).
給料はルーブルでもらっている and 給料はルーブル建てでもらっている are equally valid.

One might say the meaning is different - ルーブルで means transactions literally
done in rubles, while ルーブル建て can also mean transactions defined and displayed
in rubles. (Either way what you actually get would have the same worth,
though.)

<https://kotobank.jp/word/%E3%83%89%E3%83%AB%E5%BB%BA%E3%81%A6-586210>

> ドル‐だて【ドル建て】 債権・債務の関係をドル貨に換算した金額で表示すること。




It depends on the construction. 給料はルーブルです is fine in casual speech, but when
written in business context, it may look slightly sloppy (only slightly).
給料はルーブルでもらっている and 給料はルーブル建てでもらっている are equally valid.

One might say the meaning is different - ルーブルで means transactions literally
done in rubles, while ルーブル建て can also mean transactions defined and displayed
in rubles. (Either way what you actually get would have the same worth,
though.)

<https://kotobank.jp/word/%E3%83%89%E3%83%AB%E5%BB%BA%E3%81%A6-586210>

> ドル‐だて【ドル建て】 債権・債務の関係をドル貨に換算した金額で表示すること。

