Treatment of payment for referral bonus to customers

Hi,

please let me know about the accounting treatment for the payment made to existing customers who win cash prizes on successful referral of our products.

1.Do we require any invoice from his for the payment?
2.Will the TDS attract it?
3. Do we need to take declaration under section 206AB in this regard.
4. How we set off payment in our book if we do not collect invoices for them?

please assist me in this regard

thanks