Dear Suresh,
The percentages of 70% for VAT and 70% for Service Tax are fixed to ascertain the component of Service and Supply in the transaction and as such, we cannot derive the converse by stating that the base value is increased to that extent. If that would be the case, as you said, the base should be 70+70 = 140.
But that is not what is intended. It only means that for the purpose of VAT, 70% of the value represents supply and for the purpose of Service Tax, 70% of the value represents service. These provisions are framed considering that the assessee is unable to ascertain the individual components of supply and service and thus, composition scheme is chosen. If the assessee is able to separate them, then this method is not applicable.
Entries for the same would be as follows:
Descripttion Amount Rs. Amount Rs.
Debit Expense A/c (Value of Service) 100,000
Debit Expense (VAT Portion - Input Credit 10,150
is not available in composition)
Debit Service Tax Input Credit account (Total
Service Tax) 8,652
Credit Supplier/Service provider 1,14,476
Credit Service Tax payable A/c (Reverse charge) 4,326
Please refer to Notification No. 24/2012 - ST and 30/2012 - ST, for information on the amendment.