If you go by circular 715 of 1995 reimbursement to C&F Agent for freight attracts TDS as he is not an agent of the shipping company.
There has always been disputes with department regarding TDS on duty amounts paid by CHA for customs duty etc. There are conflicting views as the sections speak on payment of any sum. However, there is also a judgement of Supreme Court (1999) in section 195 that if any amount is paid as a reimbursement for expense abroad and the same is not taxable in India, no TDS is to be deducted provided there is no profit element in the reimbursement. Usually the same principal would apply in these cases also. However, department always contends that the professional or the agent while investing money for you has the motive of profit in the fees that he receives and therefore it is part of his income and TDS should be applied.
Therefore if the professional or agent has invested money for you and you pay him later, you have to apply TDS but not service tax. However, if you are giving cash to the agent and tell him to pay the ESIC dues, there is no service tax or TDS as he is simply carrying your cash (as an imprest a/c) to go and pay your money and you get the receipt from ESIC in your name.
The last para above is what our accountant does. If amounts are small he gives cash, takes a confirmation of the person that he has taken cash to go and make the government payment and then attaches the challan copy when it comes. The best obviously as is done for large payment is to issue blank cheque with not over amount (ceiling) and name of department and preferably the a/c number on face or at least behind the cheque and let the agent fill the amount as necessary.
Harshall, you are right. The problem is there if the agent pays first and then you reimburse him. Ditto if you pay advance as at that time no payment of tax or ESIC has been made and the whole thing has to be treated as agents income. Best is to give cash to pay on your behalf and get the cash received challan in your name. There is no limiton payment of cash to government. Your agent can take cash from you to make payments as much as your employee can do the same.