上【じょう】

上, read じょう, goes straight onto a noun with no particle and means "in terms of" or "as far as … is concerned": what follows holds within that field or from that point of view. Many of these compounds work like English "-wise" or "-ly": ほうりつじょう法律上 is "legally", しごと仕事じょう上 "for work".

Before a noun it takes の.

"Only on paper": 上は

With は, the frame becomes a contrast: it is true in that respect, and the rest of the sentence hints that the reality is different. ひょうめんじょう表面上 ("on the surface") and けいさんじょう計算上 ("on paper") are the usual nouns.

Usage notes

These go beyond the main "in terms of" frame.

Fixed compounds

Some compounds have set meanings of their own: じじつじょう事実上 is "in effect, de facto", れきしじょう歴史上 "in all of history".

Reading and register

Here 上 is read じょう, not うえ, and nothing comes between it and the noun. The compounds belong to writing, news and business; in conversation きごう〜てき的には or きごう〜のめん面では often does the same job.