law: Indian Contract Act, 1872 
  61. Application of payment where
  
  neither party appropriates
  Where neither party makes any appropriation, the payment shall
  
  be applied in discharge of the debts in order of time, whether they are or are
  
  not barred by the law in force for the time being as to the limitations of
  
  suits. If the debts are of equal standing, the payment shall be applied in
  
  discharge of each proportionably