According to the footnotes on the iPhone XS page: 11. eSIM will be available later this year through a software update. Use of eSIM requires a wireless service plan (which may include restrictions on switching service providers and roaming, even after contract expiration). Not all carriers support eSIM. Use of eSIM in iPhone may be disabled when purchased from some carriers. See your carrier for details. To learn more, visit https://support.apple.com/kb/HT209044.