Input tax credit for stock: transitional allowance subject to conditions and recovery if earlier law liability surfaces. Transitional rules allow a registered taxable person to take credit for taxes and duties paid under the earlier law on inputs and inputs contained in semi finished or finished goods held in stock on the appointed day, if such inputs are for taxable supplies, the person would have been eligible for credit under the earlier law but for non registration or exemption, is eligible under the new Act, possesses invoices or prescribed documents issued within twelve months before the appointed day, and the credit amount is calculated per generally accepted accounting principles; such credit is recoverable as an arrear if found recoverable under proceedings under the earlier law.