USIM shortage hits SK Telecom after data breach

SK Telecom’s hacking crisis has escalated into an unprecedented “USIM shortage,” sparking growing complaints and confusion among customers. Critics argue that the company’s rushed announcement of a free USIM replacement plan—without securing sufficient inventory—has only fueled subscriber anxiety.

Starting at 10 a.m. on April 28, SK Telecom launched its free USIM replacement program at more than 2,600 T World stores nationwide. By 8 a.m., two hours before the official start time, long lines had already formed. However, many customers were turned away due to shortages, and the online reservation system for USIM replacement—also launched that day—became overwhelmed with more than 100,000 simultaneous users, leading to significant connectivity issues.

Currently, SK Telecom has a stock of only about one million USIM cards. Although the company plans to secure an additional five million units by the end of next month, this still falls far short of what is needed. With 23 million SK Telecom subscribers and 1.87 million additional users on budget carriers using SK’s network, demand could reach around 25 million USIMs.

Given the supply situation, the replacement process could take several months. SK Telecom has already requested other telecom providers to share their excess USIM stock. However, an industry insider noted, “We are cooperating with SK Telecom’s request, but few carriers have reserves comparable to Korea’s largest telecom operator.”

Amid the turmoil, some mobile phone retailers are aggressively offering large subsidies to attract customers, intensifying competition. A representative from the Korea Communications Commission (KCC) stated, “We are closely monitoring the market,” and warned, “Although the Mobile Device Distribution Act is set to be abolished at the end of July, it is still in effect, and any violations will be subject to investigation and inspection.”

Adding to SK Telecom’s woes, subscribers have begun preparing collective legal action. They accuse the company of an inadequate response and have launched a National Assembly petition calling for action. As of 4:30 p.m. on April 28, more than 25,000 people joined a Naver café organizing a class-action lawsuit related to the USIM data leak.


장은지 기자 jej@donga.com