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Nearly 1 million users switch mobile carriers in May in wake of SKT data breach

Published: 02 Jun. 2025, 14:37 Updated: 02 Jun. 2025, 20:45

SK Telecom's headquarters in Jung District, central Seoul is seen on May 6. [NEWS1]

In May, nearly 940,000 people switched mobile carriers — an unprecedented figure, as the number had not exceeded 500,000 in the past five years. The switch comes following a major data leak of SK Telecom (SKT), with most users moving to competitor KT.

The Korea Telecommunications Operators Association said Monday that 933,509 users switched carriers in May among SKT, KT, LG U+ and mobile virtual network operators (MVNO). The figure marks a 77 percent jump from 525,937 in March, before the cyberattack.

Number portability typically hovers around 500,000 per month, and the figure had not surpassed 600,000 in the past five years.

In January, 494,530 users switched carriers, and the number remained in the 500,000 range through February and March. But the April breach pushed the total close to 700,000 before nearly reaching 1 million in May.

KT benefited the most from the upheaval, with 196,685 users moving over from SKT in May — roughly five times the usual volume.

A notice about the SK Telecom SIM hacking incident is seen at a phone store in Jung District, central Seoul on May 12. [NEWS1]

The spike began in April, with 95,953 users transferring from SKT to KT that month.

LG U+ also saw gains. In May, 158,625 people switched from SKT to LG U+, while in April, 80,605 made the move — about double the monthly average.

MVNOs also gained users. In May, 85,180 people switched from SKT to an MVNO, about 30,000 more than usual. Meanwhile, only about 10,000 users each moved from KT, LG U+ and MVNOs to SKT.

Customers wait in a long line to replace their SIM cards in front of an official SK Telecom retailer in Seoul on May 20. [YONHAP]

In February and March, prior to the breach, some 40,000 users switched to SKT from both KT and LG U+, and over 20,000 from MVNOs.

In April, SKT suffered a security breach that led to the leak of user data related to SIM cards. The company has responded by offering free SIM card replacements and increasing subsidies for device upgrades and support for new smartphones.

Translated from the JoongAng Ilbo using generative AI and edited by Korea JoongAng Daily staff.
BY LEE HAY-JUNE [[email protected]]