PromptPay: Thailand instant payments by ID or mobile

PromptPay is Thailand instant payment system, launched in 2017 and overseen by the Bank of Thailand, and it lets a person or business send money instantly using a national ID number, a mobile phone number, or a bank account number, 24 hours a day, 7 days a week. A payment sent by PromptPay settles in seconds, and the payer sees the recipient name before confirming, which is the control that prevents most mistaken payments. PromptPay is operated by National ITMX, and it connects every major Thai bank, so a customer of any bank can pay a customer of any other bank instantly, which is the point of a national system. Source: Bank of Thailand, PromptPay; National ITMX. Why PromptPay exists is that Thailand wanted a national instant payment system that was simple enough for everyone, including people who had never used internet banking, and cheap enough that small merchants would accept it. Before PromptPay, a transfer between banks took hours, a transfer to a different bank cost a fee, and cash was the default for small payments, which is expensive to handle and hard to trace. PromptPay answers by making the transfer instant, by letting the payer use a mobile number instead of an account number, and by keeping the fee low or zero for most personal payments, so a street vendor can accept a payment by showing a QR code, and the money is in the account in seconds. The parties are the payer and the payee, their banks, which must be PromptPay participants, National ITMX, which operates the system, and the Bank of Thailand, which oversees it and settles the payments. The addressing is by proxy: a national ID, a mobile number, or an account number, and the proxy is registered to one account at one bank, so the payer bank looks up the proxy, finds the account, and shows the payee name. The QR code is the merchant version of the same idea: the customer scans the merchant QR code, the merchant name and amount appear, and the customer confirms, so the merchant does not need a terminal and the customer does not need cash. How it works is shown by a worked example. A customer in Bangkok buys goods for THB 1,850 from a market stall on a Sunday at 11:00, scans the stall PromptPay QR code, sees the stall name and THB 1,850, confirms, and the payment settles in seconds, crediting the stall account at 11:00:04. The stall owner sees the credit immediately, hands over the goods, and does not need to count cash or worry about a counterfeit note. For a larger payment, a company in Bangkok pays a supplier THB 420,000 by PromptPay using the supplier tax ID on a Monday at 09:00, and the supplier account is credited within seconds, with the invoice number in the reference, so the supplier reconciles it automatically and dispatches the goods the same day. On success the payment is final in seconds, the receiver can use the money immediately, and the cost is low, so the system is used for everything from a THB 20 coffee to a THB 420,000 supplier payment. On failure the payment can be rejected, for example because the proxy is not registered or the account is closed, and the rejection is immediate, so the payer knows at once. The failure that matters most is a payment sent to the wrong proxy, because the payment is final, so the recovery is a request to the receiver to return the money, and the bank follows its mistaken payment process, which depends on the receiver cooperation and can take days. The data in a PromptPay payment is the payer and payee identification, the proxy, the amount in Thai baht, and the reference. The proxy is the field that matters most, because a mobile number that has been reassigned to a new owner, or a national ID that is registered to an old account, sends the money to the wrong person. A BA must specify the proxy lookup, the name confirmation, the QR code handling, the limits, and the process for updating a proxy when a customer changes banks or phone numbers, because each of those is a customer promise and a source of mistaken payments. Edge cases show the limits. Each bank sets its own per-transaction and daily limits, so a THB 100,000 payment that one bank allows may be blocked by another, and the customer must be told the limit before they try. A QR code payment where the amount is entered by the customer can be for the wrong amount if the customer mistypes, so the merchant should use a dynamic QR code with the amount embedded, and the requirement should prefer dynamic codes for larger amounts. A payment sent on a public holiday settles instantly, because PromptPay never closes, but the receiving bank reconciliation may still run on business days. The effect on the bank is a service customers expect, and a reduction in cash handling and batch payment volume, because customers who can pay instantly by mobile number will not queue to pay cash. The effect on the customer is instant payments by mobile number or ID, at any hour, with a name check that prevents most mistakes, and a QR code that lets a small merchant accept payments without a terminal. The effect on operations is a 24/7 service with fraud screening in milliseconds, and a mistaken payment queue that must be worked quickly, because the customer who sent money to the wrong person wants it back today. What a BA, PO or SME must understand is that PromptPay is a national system with proxy addressing, and the proxy is the addressing, the name confirmation is the control, and the instant settlement is the value. The requirement must name the proxy types, the lookup, the name confirmation, the QR code handling, the limits and the mistaken payment process. The test is to send one payment by mobile number, check that the name was shown before confirmation, that the credit arrived in seconds, and that the reference matched, because if any of those fails, the service is not working. Further reading: Bank of Thailand, PromptPay; National ITMX, PromptPay service description. Last reviewed 7 November 2026.