Service tax on security deposit with mobile service operator

yes if it non-refundble & adjusted against call charges.

Agreed with learned members above. If its non-refundable and adjustible against call charges, then service tax shall be applicable.

No, if it is a refundable security deposit, it is not taxable. However, if later on, it is adjusted against call charges then first service tax on call charges has to be levied and after that it has to be adjusted against security deposit.