There is a wide range of legislative demands and requirements when you export and import goods. There are also various documents and forms which must be completed and submitted at customs authorities. Goods must be properly classified into correct customs nomenclature and declared  with correct customs tariff. This all means extensive administrative work and also numerous threats of incorrect goods tariff and nomenclature classification, customs forms completed incorrectly, documents missing, braking of customs codes. All this can result in serious issues with customs authorities, penalties, adjustments statements (duty adjusted retroactively), excise duty adjustments etc, That is why it is highly reasonable to turn to professionals.