obveznik

1. (usually with poreski, vojni) person liable; obligor
   Svaki poreski obveznik mora da preda prijavu do kraja marta. — Every taxpayer must file a return by the end of March.
   Vojni obveznici su ranije morali da služe vojni rok. — People liable for military service used to have to do their national service.

Mostly used in official phrases: poreski obveznik 'taxpayer', vojni obveznik 'person liable for military service'.