Interest on delayed tax payment: statutory interest accrues from the due date and applies to undue input tax credit claims. Imposes an obligation to pay interest where a person fails to pay tax within the prescribed period; interest is charged for the period the tax remains unpaid at a rate notified by the Central or a State Government on the Council's recommendation, with calculation starting from the first day the tax was due. Undue or excess input tax credit claims attract interest at the prescribed rate for the period computed in the prescribed manner.