I’m Endo from IIJ Thailand.
In a small alley in Bangkok, there is a street stall selling pad gaprao, Thai basil stir-fry over rice, for around 60–80 baht, or about 300–400 yen. When you are ready to pay, the vendor simply shows you a laminated QR code.
You scan the QR code with your banking app, enter the amount, and tap send. A few seconds later, the vendor’s phone receives a payment notification. Without stopping her cooking, she simply nods to confirm that the payment has arrived. The whole process takes only a few seconds, with no coins to count and no change to worry about.
In Thailand today, a smartphone is often all you need for everyday payments, whether you are in an upscale shopping mall or at a small street stall. I have rarely come across a shop that does not accept QR code payments. Behind this cashless way of life is PromptPay, Thailand’s real-time payment infrastructure. At first glance, it may look similar to Japan’s PayPay, but the underlying model is completely different.
The biggest difference is that PayPay and Rakuten Pay are services operated by private companies, while PromptPay functions as a national payment infrastructure. In Japan, users typically top up a balance in a digital wallet and make payments within each provider’s own ecosystem. PromptPay works differently: it connects bank accounts directly, allowing money to move from one account to another without going through a separate wallet balance.
There is no need to top up money in advance. Funds move directly from the payer’s bank account to the recipient’s account in real time. The same QR-based system can be used regardless of which participating bank or mobile banking app either person uses. Small person-to-person transfers are generally free, which helps explain why PromptPay has been adopted so widely by street vendors and small shops with thin profit margins.
What makes this possible is the use of a common identifier across banks. In a conventional bank transfer, the sender usually needs details such as the bank name, branch number, and account number. With PromptPay, the recipient’s bank account can be linked in advance to a phone number or national ID number. This allows the payer to send money by scanning a QR code or entering a phone number, without needing to know which bank the recipient uses.
This interoperability is one of the main reasons PromptPay has become so widely used, even among people who are not familiar with digital services. Users do not need to think about which payment app or bank the recipient uses, and merchants do not need to display separate QR codes for different providers.
While Japan’s cashless payment market remains fragmented across different apps, loyalty programs, and provider ecosystems, Thailand has made instant, low-cost bank-to-bank payments part of everyday life.
Watching street vendors use PromptPay so naturally makes one thing clear: successful digitalization is not simply about having advanced technology. It is about removing friction from everyday transactions and making the system open enough for everyone to use.
