Taiwan telecom warns of travel eSIM use

台灣電信業者警示：謹慎使用旅遊eSIM卡

TAIPEI (Taiwan News) — As overseas travel rebounds, Taiwanese travelers are increasingly turning to eSIM services instead of traditional roaming plans, but telecommunications experts warn low-cost options may pose cybersecurity and privacy risks, per CNA.

Travel eSIMs have gained popularity because they are inexpensive and easy to activate, often requiring only a payment and the scanning of a QR code. Many providers also offer flexible plans covering multiple countries or regions, with charges based on data usage rather than time limits.

However, recent reports have raised concerns that some travel eSIM services route data through Chinese telecommunications networks, potentially exposing users to security risks.

Chunghwa Telecom Chair Alex Chien (簡志誠) said some eSIM operators do not adequately implement “Know Your Customer” verification procedures, making the origin of network services and data transmission routes difficult to identify. And because internet traffic is often routed through the country where the service is registered, Chien said unclear network origins can create cybersecurity concerns.

Technology commentator Hung Sheng-yi (洪聖壹) said uncertain network routing in some regions could increase the risk of data interception during transmission. He warned that eSIM profiles obtained from unknown sources may contain malicious DNS settings, request excessive permissions, or expose users to data theft.

Hung said some low-cost plans rely on international roaming resale arrangements, which can trigger unusual account verification requests. This can cause services to flag logins as originating from a different location, affecting communication functions such as FaceTime.

Chien acknowledged that roaming with a user's original phone number is generally more expensive than purchasing a travel eSIM but said it offers greater security and service reliability. "If there are any problems, you can contact customer service," he said.

He said companies like Chunghwa Telecom aim to provide affordable services but face infrastructure and operational costs that differ from those of eSIM providers, which may benefit from wholesale purchasing arrangements or promotional subsidies.

Addressing concerns that original-number roaming may be slower than connecting directly to a local network through an eSIM, Chien said that is not necessarily the case. He said roaming services often provide better connection quality and stability because telecommunications operators maintain direct agreements with local partners, while eSIM traffic may be routed through more complex networks that can affect performance.

Hung added that one of the biggest advantages of original-number roaming is that users retain access to their regular phone number, allowing them to receive one-time passwords and banking text messages without interruption. For travelers who still want to use eSIM services, he recommended downloading plans only from trusted sources.

He also advised consumers to verify the telecommunications carrier and network provider, compare pricing based on cost per gigabyte, and confirm that customer support and company information are clearly available. Users should also be cautious if an eSIM activation process requests access to sensitive permissions such as contacts, photos, Bluetooth, or location data, he said.