Notional credit timing under Modvat: notional credit cannot be deferred beyond actual duty credit at input receipt. Notional credit under Modvat must be taken no later than the date when actual duty credit was taken on receipt of inputs; in the absence of a specific Modvat provision allowing deferred recognition, the Law Ministry has confirmed the Board's instruction that deferred notional credit is not permissible, and aggrieved assessees may pursue appellate remedies.