Breakdown of Abban az esetben, ha nincs melléklet, hiánypótlás kell.
Questions & Answers about Abban az esetben, ha nincs melléklet, hiánypótlás kell.
Yes — ha already means if, so abban az esetben, ha ... is more formal and heavier than just ha ....
- ha nincs melléklet, ... = if there is no attachment, ...
- abban az esetben, ha nincs melléklet, ... = in that case / in the event that there is no attachment, ...
This kind of wording is very common in official or bureaucratic Hungarian. In everyday speech, people would often just say:
- Ha nincs melléklet, hiánypótlás kell.
So the longer opening is not wrong at all — it just sounds more formal.