A duty-free shop: a store that sells goods exempt from consumption tax or customs duties, typically found at airports and catering to international travelers.
空港の免税店で香水を買った。
I bought perfume at the duty-free shop at the airport.
免税店ではパッケージや身分証の提示が必要な場合がある。
Duty-free stores may require presentation of packaging details or identification.
海外旅行の際は免税店でお土産を買う人が多い。
Many people buy souvenirs at duty-free shops when traveling abroad.