Compare: 上 vs 上

上かみ

upper reaches (of a river); upper stream

上じょう

from the standpoint of; from the viewpoint of; with respect to; in terms of; as a matter of; in view of; so far as ... is concerned

かみ上

N5CommonNoun

upper reaches (of a river); upper stream

じょう上

N5CommonSuffix

from the standpoint of; from the viewpoint of; with respect to; in terms of; as a matter of; in view of; so far as ... is concerned

戸籍上(じょう)の縁(えん)は切れても、昔日の絆はそのままだ。

Our connection may be cut on paper but the bonds of old remain as they were.

これはおそらく戸籍上(うえ)の出生年月日を調べた上(うえ)で修正したのではないかと思います。

I believe this may be a correction after investigation of his date of birth in the family register.