A sign reading "Only Domestic Cards are Accepted" is displayed above KTX ticket kiosks at Seoul Station. Only two machines accept international cards, with one out of order, Wednesday. Korea Times photo by Jung Da-hyun

Despite the Seoul Metropolitan Government's ambitious goal to attract 30 million international tourists annually, many foreign visitors still face difficulties when trying to pay for public transportation in the city.

At Seoul Station, the city's largest transportation hub serving four subway lines, the high-speed KTX service and regular trains, many international visitors still face challenges paying for transportation with foreign-issued credit or debit cards.

When a Korea Times reporter visited the station on Wednesday, 20 kiosks were available for purchasing KTX tickets, but only two accepted foreign credit cards. One of those machines was out of service.

The situation is even more limited for the subway, where foreign cards are not accepted as a means of payment. Tourists must either buy a rechargeable T-money card or the city's unlimited transit pass, the Climate Card, from stations or convenience stores. Alternatively, they can use cash to purchase single-journey subway tickets.

A convenience store inside Seoul Station, however, had a sign stating that it does not carry Climate Cards.

Seoul Metro, which operates parts of Lines 1, 3 and 4, and all of Lines 2, 5, 6, 7, 8 and 9, acknowledged the inconvenience faced by international visitors. However, the company said that upgrading the system to accept international cards would entail significant costs.

To ride the subway, passengers must use a transportation card compatible with Korea's domestic PayOn standard, which foreign-issued credit cards do not support. This essentially renders global cards like Visa and Mastercard useless for payment.

An "open-loop" payment system, which would allow riders to use international credit cards and digital wallets, depends on compatibility between global card networks and Korea's transportation payment infrastructure. However, such integration would require costly upgrades or the replacement of existing fare terminals, the subway operator said.

"While the cost of upgrading the system is a major concern, there are also doubts about its effectiveness, as expected usage by foreign visitors may be limited," a Seoul Metro official said.

Even if the physical infrastructure were upgraded, a challenge would remain in developing a fare settlement system compatible with Korea's complex integrated transfer discount system, the official added.

"This would require navigating conflicting interests and regulatory hurdles among local governments, transit card companies, credit card firms and public transportation operators," the official said.

The Seoul Metro official said the issue is under internal discussion, but no concrete plans have been established yet.

KORAIL, which operates the KTX, was not immediately available for comment on the issue.