The 20-baht flat fare for all electric train lines will become effective from Sept 30, with Thai passengers required to register for the programme via the Tang Rat application, according to Transport Minister Suriya Jungrungreangkit.
The policy will allow Thai citizens to travel across all train lines with a maximum fare of 20 baht per trip, regardless of how many lines are used.
Mr Suriya, who is also a deputy prime minister, said the Tang Rat app will serve as a clearing house that will ensure fair earnings for all lines. Passengers will need to link their existing EMV (Europay, Master Card or Visa) contactless cards or transit cards, such as Rabbit or MRT Plus, during registration, which will start in August.
The app will track travel routes to determine the fare, ensuring passengers are charged no more than 20 baht while allowing the government to compensate operators for any fare differences.
Despite the unified fare, passengers cannot yet use one card across all lines, as each operator currently supports different card systems. For example, the BTS Skytrain only accepts Rabbit cards, while EMV cards are accepted by six lines, including the Red, Blue, Purple, Pink, and Yellow Lines.
To make the system financially viable, the government will establish a joint ticketing fund, with an estimated eight billion baht in annual subsidies drawn from the Mass Rapid Transit Authority of Thailand's (MRTA) accumulated profit of 16 billion baht. Additional funding will be allocated from the national budget.
Legal amendments will be made to allow the MRTA to utilise its reserves for this fund, with finalisation expected by September.
The agency will also negotiate changes to existing concession contracts with the private operators of the Blue, Yellow, and Pink Lines to comply with the 20-baht flat fare policy.
In the long term, the government aims to buy back concessions from private operators of electric train lines within two years.
By the end of next year, the system is expected to support QR code payments via mobile phones, offering greater convenience.
The flat fare scheme will be available only to Thai citizens, excluding foreign tourists and welfare cardholders, who must continue paying standard fares.