The waiver will be effective until the end of July, it said in a statement.
"THAI waived the fee due to concern for customer safety and convenience," said Wiwat Piyawiroj, THAI vice president of Sales and Distribution, Thailand and Indochina.
The fee has been waived for changes to flights and routing of THAI tickets booked roundtrip from Bangkok to Seoul and Bangkok to Busan. This also covers domestic flights issued prior to June 8, 2015 for travel destined for Seoul and Busan, initially intended for travel now until July 31. The tickets must have been booked by a THAI ticketing office, THAI ticket agent, or through www.thaiairways.com.