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SK Telecom loses more than 34,000 customers to rival carriers after hacking incident

Published: 29 Apr. 2025, 13:58 Updated: 29 Apr. 2025, 14:29

A notice at a SK Telecom branch in Seoul says the store has run out of universal subscriber identity modules (USIM) on April 28 the same day the carrier started a replacement service for all subscribers following a data breach. [YONHAP]

More than 34,000 SK Telecom subscribers switched to rival carriers on Monday, the same day the company started offering subscriber identity module (SIM) replacements following a data breach, according to industry sources on Tuesday.

A total of 34,132 customers left SK Telecom, while 8,729 new users joined, resulting in a net loss of 25,403 subscribers, data showed Tuesday.

Approximately 60 percent of the departing users moved to KT, with the remainder transferring to LG U+. KT saw 21,343 new subscribers, and LG U+ added 14,753.

The total number of users leaving SK Telecom is expected to be even higher when including those who switched to budget carriers.

On April 18, SK Telecom discovered that a hacker had leaked some USIM-related customer information through malicious code. Rising concerns over the breach prompted an uptick in users leaving SK Telecom starting from Saturday.

Until earlier this month, SK Telecom’s daily subscriber losses had not exceeded 200.

But 1,665 users left on Saturday, with the number increasing rapidly afterward.

SK Telecom stores and retail partners reportedly offered sizable subsidies over the past weekend to attract customers from other carriers, which may have contributed to the 8,729 new sign-ups.

SK Telecom is the largest mobile carrier in Korea with about 23 million subscribers. KT ranks second with around 15 million users, while LG U+ follows with slightly more than 10 million.

Translated from the JoongAng Ilbo using generative AI and edited by Korea JoongAng Daily staff.
BY JEONG JAE-HONG [[email protected]]