How do I file an amended declaration when I learn that the declared tax amount is in deficiency?

When a duty payer learns that the declared tax amount is in deficiency after six months (correction period) from the date on which the tax was paid, he/she shall file an amended declaration. Any person who intends to file an amended declaration shall send a Correction Application of Import/Tax Declaration (Annex no.6 form) of Notification on the Import Declaration Affairs to the KCS customs system and submit evidential data to the head of a customs office. In this case, the duty payer shall pay the relevant customs duty by the next day of the date on which the amended declaration was filed.