law: Payment of Bonus Act, 1965 
  3. Establishments to include departments, undertakings and
  
  branches 
  Where an establishment consists of different departments or
  
  undertakings or has branches, whether situated in the same place or in
  
  different places, all such departments or undertakings or branches shall be
  
  treated as parts of the same establishment for the purpose of computation of
  
  bonus under this Act:
  PROVIDED  that where for any accounting year a separate
  
  balance-sheet and profit and loss account are prepared and maintained in
  
  respect of any such department or undertaking or branch, then, such department
  
  or undertaking or branch shall be treated as a separate establishment for the
  
  purpose of computation of bonus, under this Act for that year, unless such
  
  department or undertaking or branch was, immediately before the commencement of
  
  that accounting year treated as part of the establishment for the purpose of
  
  computation of bonus.