Police recently arrested nine people accused of luring cash-strapped borrowers with small loans to activate prepaid SIM cards in their own names, then selling the lines to voice phishing rings. The group lent 100,000 won for each SIM activated and collected 150,000 won a month later, an annualized rate of about 608% — more than 30 times the legal ceiling of 20%. Investigators found that 4,185 prepaid SIM cards obtained this way were used in schemes including fraudulent stock-tip chat rooms.
Detected cases of burner phones — untraceable lines registered under someone else's name, long described here as a breeding ground for crime — are climbing again. As voice phishing and online scams grow more sophisticated, the methods used to secure such lines have also become more elaborate, including tie-ups with illegal lending. The government has responded with steps such as facial recognition at the point of activation, but critics say gaps remain, including identity theft using foreigners' names and activation routed around tighter carriers.
Police caught a total of 265,447 burner phones over the six years from 2020, when the National Police Agency began keeping manual statistics, through last year, according to data obtained by The Seoul Economic Daily through the office of Rep. Chae Hyun-il of the Democratic Party of Korea on the 18th.
Cases numbered 55,141 in 2021 and 53,104 in 2022 before falling to 30,577 in 2023. They then surged to an all-time high of 97,399 in 2024. After rules were tightened from March last year, requiring verification that identification documents are genuine when a phone is activated, the figure plunged to 20,303 last year.
Signs of a rebound have emerged this year. Police detected 15,446 burner phones from January through July, already 76% of last year's annual total. If the current pace holds, this year's total is likely to exceed last year's.
As voice phishing and online scam operations expand their bases to Cambodia, Malaysia and other countries, the supply chain feeding them burner phones has evolved as well. The criminal mobile unit of the Gangwon Provincial Police Agency late last year referred six people to prosecutors in custody, including the domestic ringleader who supplied phones to a Cambodian phishing operation, and referred 53 others without detention. The phones they supplied were used in investment fraud, no-show scams in which callers posed as military units, and voice phishing built around fake kidnappings, with losses estimated at about 3.8 billion won.
Activations through the country's three major carriers have also risen sharply this year. Police detected 4,292 burner phones on the three carriers' networks from January through July, or 82.8% of last year's annual total of 5,187. Analysts say demand may be shifting to the major carriers' lines as rules on budget mobile operators tighten. Budget carriers accounted for 74.3% of burner phones detected last year, down sharply from 92.3% in 2024. Activations had long been concentrated on budget carriers, where lines were relatively easy to obtain, but criminal groups appear to be seeking other routes since the rules were tightened.
Lines registered under foreigners' names are another blind spot. Some carriers recruit subscribers overseas to build their foreign customer base, and questions persist over whether identity checks are adequate. Concerns have grown in particular with the arrival of services that accept applications before a customer enters the country and activate the line on arrival, prompting calls for closer scrutiny of possible identity theft. Foreigners' names accounted for 73.3% of burner phones detected in 2024, according to the National Police Agency.
The government plans to introduce facial recognition into the activation process from July this year and to improve the system for verifying identification documents on lines held by foreigners. But recruitment and trading of burner phones continue through social media platforms such as Telegram, prompting calls for measures that block identity theft at the point of activation.
"Burner phones are exploited as tools for voice phishing and violent crimes including drugs and gambling," Chae said. "Police and carriers need to build a tight management and response system that can block identity theft from the moment a line is activated."
