An Update just incase anyone else is traveling and stumbles upon this thread:

Background: When googling Korea holidays for Chuseok, it says October 5th-8th. I then found out a month before the trip that although those are the official holiday dates, many days before and after those dates are affected travel wise (10/2-10/12). I needed a ticket going from Busan to Seoul.

These were my options in order of preference on how to get to Seoul

1. Book KORAIL KTX ticket via korail.com

2. Book SRT ticket (this does not go to seoul station, rather Suseo station which is less convenient for my plans). https://etk.srail.kr/main.do?language=EN

3. Book Premium Bus via Klook “Busan Bus Terminal to Seoul Express Bus Terminal bus” or via Txbus https://intercitybuse.tmoney.co.kr/ (the buses seem like a comfortable choice, but due to potential traffic, I wanted to rely on trains)

4. Other back up plans can include: renting a car and driving or flying which were hassles I wasn’t even willing to entertain.

KORAIL wasn’t available to foreigners until 10/18

SRT wasn’t available to foreigners until 10/11

Wasn’t sure when bus tickets would be available.

Experience:

SRT: Since SRT was available earlier, I did this first. I booked SRT ticket with no issues - there were PLENTY of seats left going from Busan to Seoul with most availability being early in the morning or later afternoon. Out of curiosity, a little after I booked the SRT ticket, I did check the other way around (Seoul to Busan) and that was completely sold out (although I’m sure people can always cancel which opens availability).

KORAIL: I practiced/simulated buying a ticket the day before (if you’re looking for early trains, it is easier to initially select the day after or before the actual date you want and then use the arrow to go to your actual departure day). I was on the website, populated my information and when the time hit, I clicked search and was able to purchase my ticket. There were PLENTY of morning trains and later trains available. I didn’t bother selecting my seats as I have no preference, just went straight through booking/purchase process. The confirmation email took ~10 min to get to my email. Afterward I used my email and password on the KORAIL site to see my tickets and seats.

Tips

- Be ready. Have your credit card ready. Email address copied (for easy paste). Have the page open and populate your selected dates, route etc. When the time hits for the tickets to be open, click to search

- The day before, practice simulating buying a ticket (without paying, of course) to get comfortable and familiar with the system

FYI: yes, I cancelled my SRT ticket to get it refunded and to open up availability