(1) In any of the following subparagraphs, the head of a customs office may periodically select persons that are subject to customs duty investigations in order to verify the appropriateness of their declarations (hereinafter referred to as "periodical selection") and may investigate them. In such cases, the head of a customs office shall select them fairly in accordance with objective standards:
1. Where the head of a customs office deems that exporters or importers have been suspicious of filing a negligent declaration after he or she conducts a periodical analysis of sincerity of their declarations;
2. Where it is necessary to verify whether declarations filed by duty payers that have not been subject to investigation for the preceding four years by considering type, scale of their business, etc., as prescribed by Presidential Decree;
3. Where a sample tax investigation is to be conducted under a random sampling method.
(2) In any of the following subparagraphs, the head of a customs office may conduct customs duty investigation other than investigations following periodical selection: <Amended on Aug. 13, 2013; Dec. 19, 2017>
1. Where a duty payer fails to perform any obligation to cooperate in the payment of customs duties, such as filing a declaration or application or submitting data for determination of a customs value, as provided in this Act;
2. Where there is a specific report, etc. on duty evasion against exporters or importers;
3. Where details of a declaration contains any data corroborating a suspicion of duty evasion or error;
4. Where a duty payer provides or offers to provide any money or valuables to any customs officer in connection with the duties of the customs officer.
(3) Where the head of a customs office shall assess and collect customs duties pursuant to Article 39 (1), he or she may conduct an investigation to determine the duty base and the amount of duty.
(4) The head of a customs office may not investigate persons whose scale of export and import declaration for the preceding two years is not more than certain amount and who satisfy requirements prescribed by Presidential Decree: Provided, That the same shall not apply where it is evident that they have under-reported the customs duties based on objective evidentiary data.[This Article Newly Inserted on Dec. 31, 2011]