Service Tax Registration number is a PAN based 15 digit alpha numeric numbers e.g. ASDCE1588ST001.
The first part denotes (10 characters – alpha numeric) Permanent Account Number issued by Income tax authorities to the concerned person to whom the Service Tax Registration Number is to be allotted. Second part comprises of a fixed 2 character alpha code – ST (Service Tax). This is followed by 3-Character numeric code representing the registeredPremises or Office of the service provider
The Service Tax Registration Number has to be quoted on GAR–7 Challans covering deposit of Service Tax, Cess and other dues to the Government.