Dear sanjay,
payment by way of voucher is irrelevant in respect of TDS regulation. TDS shall be deduct even on credit & provisions of expenses if the threshold limit and required criteria of appropriate expenses is meet. as per the TDS norms TDS will be deduct either on credit or payment whichever is earlier therefore payment by cash, cheque or signing voucher is irrelevant,
Thanks & Regards
V SHAKYA
HR & Labour, Corporate Laws Advisor