Upass is a pre-paid card for the transportation system in Seoul

Seoul

Seoul , officially the Seoul Special City, is the capital and largest metropolis of South Korea. A megacity with a population of over 10 million, it is the largest city proper in the OECD developed world...

 and its suburbs. This card is issued by Seoul Metropolitan Bus Operator Association and eB Card. Its parent-generation card is Seoul Transportation Card, a world-first commercial-used RF card for transportation (first used in June, 1996)¹. You can use old Seoul Transportation Card and T-money

T-Money

T-money is a rechargeable series of cards and other "smart" devices used for paying transportation fares in and around Seoul and other areas of South Korea. T-money can also be used in lieu of cash or credit cards in some convenience stores and other businesses...

 along with Upass.

Technology

Upass, and older Seoul transportation card system is based on MIFARE

MIFARE

MIFARE is the NXP Semiconductors-owned trademark of a series of chips widely used in contactless smart cards and proximity cards. According to the producers, billions of smart card chips and many millions of reader modules have been sold...

 Standard, Ultralight and PROX technology.

Use

Many kiosk around Seoul sells various type of Upass cards. Major banks and credit card companies, including most favored Kookmin Bank

Kookmin Bank

KB Kookmin Bank or KB is the largest bank by both asset value and market capitalization in South Korea.The bank is led by Kang Chung-Won who previously worked for Seoulbank and oversaw its sale to competitor Hana Bank before moving to Kookmin.Kookmin intended to take over Korea Exchange Bank, a...

 and BC Card

BC Card

BC Card is Korea's biggest credit card company. It is headquartered in Seoul, South Korea. It made up of 11 member companies. It is named "BC" for Bank & Credit.-Member companies:*Woori Bank*Nonghyup*SC First Bank...

, issue Upass compatible credit/debit cards marked with PayOn, MasterCard

MasterCard

Mastercard Incorporated or MasterCard Worldwide is an American multinational financial services corporation with its headquarters in the MasterCard International Global Headquarters, Purchase, Harrison, New York, United States...

 Paypass or Visa

Visa

Visa or VISA may refer to:* Visa , a document issued by a country's government allowing the holder to enter or to leave that country...

 Paywave. Upass is accepted by:

• All Seoul
  Seoul
  Seoul , officially the Seoul Special City, is the capital and largest metropolis of South Korea. A megacity with a population of over 10 million, it is the largest city proper in the OECD developed world...
  
  , Gyeonggi-do
  Gyeonggi-do
  Gyeonggi-do is the most populous province in South Korea. The provincial capital is located at Suwon. Seoul—South Korea's largest city and national capital—is located in the heart of the province, but has been separately administered as a provincial-level special city since 1946...
  
  , Incheon
  Incheon
  The Incheon Metropolitan City is located in northwestern South Korea. The city was home to just 4,700 people when Jemulpo port was built in 1883. Today 2.76 million people live in the city, making it Korea’s third most populous city after Seoul and Busan Metropolitan City...
  
  , Cheonan
  Cheonan
  Cheonan is a city located in the northeast corner of South Chungcheong, a province of South Korea, and is 83.6 km south of the capital, Seoul...
  
  , Asan
  Asan
  Asan is a city in South Chungcheong Province, South Korea. It is located at , bordering the Seoul Metropolitan Area to the north. Asan has a population of approximately 250,000.Asan is known for its hot springs and is a city of spas....
  
   buses
• Seoul Subway and AREX
  AREX
  AREX, spelled A'REX as a brand name, is a South Korean railway line that links Seoul with Gimpo Airport and Incheon International Airport. The section between the two airports opened on March 23, 2007, the extension to Seoul Station opened December 29, 2010...
  
  
• Some Gyeonggi-do
  Gyeonggi-do
  Gyeonggi-do is the most populous province in South Korea. The provincial capital is located at Suwon. Seoul—South Korea's largest city and national capital—is located in the heart of the province, but has been separately administered as a provincial-level special city since 1946...
  
  intercity buses. These buses are marked with yellow and orange 'Transportation Card Accept' sticker. Note that Gyeonggi-do intercity buses often run between other areas.