I heard a foreign student installed a delivery app and got stuck. When they tried to sign up, all that appeared was "Enter your mobile verification code," and no text message came to their overseas number. Koreans almost never run into this, so they don't really know why people get stuck. ## Why the Mobile Phone Became an ID In Korea, when you get a new mobile phone line, the carrier checks your name and ID. So every single number is on record as "whose number" it is. Apps and websites take advantage of this. If they send a verification code by text message, they can confirm who you are without asking for a separate ID. It's fast and cheap, so almost every service ended up using this method. So without a Korean phone number, you get stuck at the very first step. ## The Cost of Getting a Number Getting a Korean number takes money, time, and effort. The cost varies by plan, so you need to check on the carrier's website or at a store. The time is the days you spend waiting until your alien registration card is issued. The effort is going to a store with your ID and handing in the paperwork. Travelers who stay only briefly can look into prepaid plans or SIM cards. However, whether identity verification works differs from product to product, so be sure to ask before you buy. There is also a cost to getting by without a number. You'll have fewer services you can use, and you may get blocked again on bank or government websites. ## What to do right away If you're staying a long time, getting a phone in your own name after you receive your alien registration card is the least hassle. Also check whether the sign-up screen has a verification route for foreigners. It differs from service to service, so some will help you if you ask customer service.