Under the Customs Act, 1962, if a person voluntarily pays the customs duty along with the applicable interest before the issuance of a show-cause notice, they are generally not liable for penalties. Section 28(1)(b) of the Act allows such voluntary payment, and upon informing the proper officer, no further notice or penalty is typically imposed.
However, if the non-payment or short-payment of duty results from collusion, willful misstatement, or suppression of facts, penalties may still apply, even if the duty and interest are paid voluntarily thereafter.
Therefore, while voluntary payment of customs duty and interest can prevent penalties, it's crucial to ensure that the underpayment isn't due to fraudulent or willful misconduct to avoid potential penalties.