If you are paying salary in cash and you need to get receipt of payment made, what is your standing order saying? Such aspects must be got covered under your own certified SO. However, if it is silent or you need a practical solution in today's context as revenue stamps are not available even in most cities then display on notice board a notice copy to Labour department that employees dues including salary, bonus etc henceforth if paid in cash then concerned employees have to acknowledge receipt of payment with their signature or thumb impressions there in the register.