PayNow and FAST: Singapore instant payments

PayNow and FAST are Singapore instant payment systems, and they work together: FAST, Fast and Secure Transfers, launched in 2014, is the real-time interbank transfer system, and PayNow, launched in 2017, is the service that lets people and businesses pay using a mobile number, a national identity number or a business registration number instead of an account number. A PayNow payment travels on the FAST rails, settles in central bank money, and is credited within seconds, 24 hours a day, 7 days a week. The two names describe two layers, the rail and the addressing service, and confusing them is the most common mistake a newcomer makes. Source: Monetary Authority of Singapore, FAST and PayNow; Association of Banks in Singapore. Why FAST and PayNow exist is that Singapore wanted interbank payments to be instant, and wanted them to be easy enough that anyone could use them without knowing a bank account number. Before FAST, an interbank transfer took hours or until the next business day, and before PayNow, the payer needed the full account number, which most people do not know for their friends or their landlord. FAST made the transfer instant, PayNow made the addressing human, and together they let a person split a dinner bill by mobile number and have the money arrive before the bill does, and let a business pay a supplier by business registration number without asking for bank details. The parties are the payer and the payee, their banks, which must be FAST participants, the operator of FAST, and the PayNow directory, which maps a mobile number, identity number or business number to an account. The payer bank looks up the PayNow proxy, shows the payee name, and the payer confirms, which is the control that prevents mistaken payments. For a business, the proxy is the Unique Entity Number, the UEN, so a supplier can be paid by UEN without sharing its account number, which is both convenient and a small privacy benefit, because the account number is never exposed to the payer. How it works is shown by a worked example. A company in Singapore owes a supplier SGD 48,000 for services, and pays by PayNow using the supplier UEN on a Saturday at 10:00. The company bank looks up the UEN, shows the supplier name, the treasurer confirms, and the payment travels on FAST, settles in central bank money, and the supplier account is credited SGD 48,000 at 10:00:03, three seconds later. The supplier sees the payment on Saturday, not Monday, and can pay its own staff on Monday with confidence. The payment cost the company a small fee or nothing, depending on its bank, and the remittance data carried the invoice number, so the supplier reconciled it automatically. On success the payment is final in seconds, the receiver can use the money immediately, and the sender has confirmation with the payee name, so there is no uncertainty. On failure the payment can be rejected, for example because the proxy is not registered, the account is closed, or the amount exceeds the bank limit, and the rejection is immediate. 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 relies on the receiver cooperation. The name shown before confirmation is therefore the most important control in the whole flow, and a bank that skips it is inviting mistaken payments. The data in a PayNow payment is the payer and payee identification, the proxy, mobile number, identity number or UEN, the amount in Singapore dollars, and the reference, which can carry an invoice number. The proxy is the field that matters most, because a proxy that is registered to the wrong account, or that has not been updated after the payee changed banks, sends the money to the wrong place. A BA must specify the proxy lookup, the name confirmation, the reference field, the limits, and the process for transferring a proxy between banks, because each of those is a customer promise. Edge cases show the limits. FAST has a per-transaction limit, and each bank sets its own customer limits, so a SGD 200,000 payment that one bank allows may be blocked by another, and the customer must be told the limit before they try. A PayNow payment to a business that has registered its UEN with one bank and then opened an account with another must update the registration, or payments will go to the old account. A payment sent on a public holiday settles instantly, because FAST never closes, but the receiving bank reconciliation may still run on business days, so the money is in the account but the statement may not show it until the next business day. The effect on the bank is a service customers expect, and a reduction in cheque and batch payment volume. The effect on the customer is instant payments by mobile number or UEN, at any hour, with a name check that prevents most mistakes. The effect on operations is a 24/7 service with fraud screening in milliseconds, because an instant payment cannot wait for a morning review, and a mistaken payment queue that must be worked quickly, because the customer who sent money to the wrong person wants it back today, not next week. What a BA, PO or SME must understand is that FAST is the rail and PayNow is the addressing service on top of it, and the two must be specified separately. The requirement must name the proxy types, the lookup, the name confirmation, the reference, the limits and the mistaken payment process. The test is to send one payment by mobile number on a Sunday, check that the name was shown before confirmation, that the credit arrived in seconds, and that the reference matched the invoice, because if any of those fails, the service is not delivering. Further reading: Monetary Authority of Singapore, FAST and PayNow; Association of Banks in Singapore, PayNow guidelines. Last reviewed 7 November 2026.