To conclude, customs are aware of the items you purchased at the duty-free shop.
This is because it is clearly stipulated in the Customs Act and related notices.
Related Laws and Contents
According to Article 213 of the Enforcement Rule of the Customs Act, the operator of a bonded store must record and maintain necessary information such as sales details and buyer's personal information in a manner prescribed by the Commissioner of the Korea Customs Service when selling goods.
More specifically, **Notice on the Operation of Bonded Stores Article 9 (Display and Sale in Stores)** specifies as follows.
The operator must manage the buyer's personal information and sales details electronically immediately upon sale and transmit this information to customs in real-time in the form of electronic documents.
Additionally, the operator must record the buyer's personal information and sales details in the sales ledger or manage them electronically, and record necessary details to allow item-by-item verification upon the request of the customs officer.
As such, the operator of a bonded store is obliged to record and report in real-time to customs the detailed information about the buyer and the purchased goods according to the regulations.
Therefore, customs are aware of what items and at what price travelers purchased at duty-free shops.
Please be careful to faithfully declare duty-free goods upon entry after traveling abroad to avoid any disadvantages.
[This content regarding export and import clearance regulations and their interpretations is based on the customs and trade laws of the Republic of Korea.]