Hi ​@Yejin Seo, we’ve looked into the charges and they were triggered by data usage and outgoing SMS, while your phone was connected to Korean and US networks. You can also check the usage in your Self Serve account. The charges are valid but if you would like to dispute them further you can schedule a call-back through our Koodo Assist or send us a private message on Social Media via Facebook, X/Twitter or Instagram.

For more information on how to prevent roaming charges, please check out this article https://community.koodomobile.com/plans-services-232910/easy-roam-understanding-how-you-will-be-charged-while-traveling-7811296