Cenvat credit utilisation limits clarified for fortnightly and monthly duty payments, restricting credit to balance as on cutoff dates. The circular prescribes a new RT-12 return and clarifies that while duty for fortnightly (or monthly for SSI) clearances may be paid by specified due dates, CENVAT credit utilisation for discharging that duty is restricted to the credit balance as on fixed cutoffs (15th day for the first fortnight; last day of month for the second fortnight), excluding credits accrued after those cutoffs. Assessees must submit detailed monthly credit statements segregated by fortnight, PLA extracts and supporting calculations to enable reconciliation and prevent inadmissible credit use.