Can I keep my Korean phone number when moving from a prepaid SIM to a postpaid plan?
I first used a prepaid SIM after arriving in Jeonju and now have my residence card and Korean bank account. I would like to know whether number portability is usually available and what documents or remaining prepaid balance I should check before changing plans.
Note: This is an editorial persona question created from common experiences of foreign residents in Korea.
1 Answer
Number portability from a prepaid SIM to a postpaid plan is often possible, but it depends on whether the existing number is registered under exactly the same legal identity and whether the receiving carrier supports that prepaid product. Before applying, ask the new carrier to check portability using your current number and carrier name. Bring your passport and residence card; the store may also request a Korean payment method or other documents for the postpaid credit and billing check. Requirements can differ by carrier and visa or residence period.
Do not cancel the prepaid line first, because cancellation can make the number unavailable for transfer. Ask the current carrier whether there are unpaid charges, a minimum active-period restriction, or an identity mismatch. Also ask how unused prepaid balance is handled, since it normally does not move automatically with the phone number and any refund depends on the current carrier's terms. After the transfer completes, test incoming calls, text-message verification, and mobile data, then update any bank or app records only if necessary. For current consumer and carrier rules, consult the Korea Communications Commission at https://www.kcc.go.kr and the government portal at https://www.gov.kr, and confirm the final procedure directly with both carriers before paying. Checked: 2026-08-18.