K-ETA is something you need to know before entering South Korea.

K-ETA is a travel authorization system for citizens of countries that can enter Korea without a visa (112 countries in total),
to enter Korea without a visa and receive a travel authorization by entering personal and travel-related information in advance.
You must apply for travel authorization online before arriving in Korea, which is intended to increase security and make the entry process more efficient.

Once you apply for a K-ETA, it usually takes 72 hours to be processed. 

If there is a discrepancy between the information on the K-ETA application and the information on your passport, you will not be allowed to board the aircraft/vessel.
Please check the information entered before making the final payment.

• Applicable to: All countries where entry without a visa is possible
• K-ETA is not mandatory for persons under 17 years of age, persons over 65 years of age, and diplomatic passport holders
  - Previously issued K-ETA can be used until its expiration date (3 years)
  - If you are 18 years old on the date of entry, you must obtain a K-ETA in advance to enter the country.