When comparing payment providers in Thailand, test what happens when an order changes after the customer receives its QR code. A cancelled purchase, a replacement amount and an old code on a customer's phone can create different payment outcomes. Your business needs to know which purchase was paid, through which channel, and what to do with an unexpected receipt.
PromptPay and Thai QR make this a practical provider-selection question. The useful comparison goes beyond displaying a code: it follows the order reference through payment confirmation, cancellation and reconciliation, then assesses THB payouts separately.
Start with the payment behind the Thai QR code
The Bank of Thailand describes PromptPay as payment infrastructure with several services, including corporate transfers, cross-bank bill payment and Thai QR Payment. A provider's “PromptPay supported” label therefore needs a more precise explanation of the proposed merchant service. Bank of Thailand: PromptPay
The BOT's published Thai QR standard distinguishes PromptPay credit-transfer data from bill-payment data. The bill-payment structure includes a biller identifier and reference fields. It also distinguishes reusable static codes from dynamic codes generated for individual transactions. BOT: Thai QR policy guideline and technical attachments
For an online order, ask who creates the reference, how it identifies the purchase and where it appears in the provider's reports. A dynamic code can carry useful transaction context, but its appearance alone does not establish your cancellation policy or prove that the customer paid.
Cancellation can depend on the payment channel
KASIKORNBANK's QR API page provides a specific example. It describes dynamic Thai QR and QR credit-card acceptance, with generated codes valid for ten minutes. Its cancellation explanation says a code supporting credit-card payments can still be paid through that channel until expiry after cancellation, while ThaiQR payment through the cancelled code is blocked. This is that product's published behaviour, not a universal rule for Thai providers. KBank: QR API
That distinction changes the questions to ask. Does the cancellation response refer to the code, the order or a particular payment channel? What happens to a payment already in progress? Can staff identify a receipt against the old order after a replacement request has been issued?
Request the answers for the exact service you intend to use. If your proposed route accepts only ThaiQR, do not import card-channel behaviour into its specification. If it combines channels, insist that the demonstration covers each one.
A hypothetical changed-order test
Suppose a customer receives a payment request for THB 1,200, then removes a THB 200 item. The merchant cancels the first request and creates a replacement for THB 1,000. This is a synthetic evaluation scenario, not a customer case or a claim about every Thai payment service.
Use distinct references for the original and replacement requests. Ask the candidate PSP to demonstrate the following outcomes in its test environment:
| Test | What your team should establish |
|---|---|
| Customer tries the original code | Whether payment is possible through each supported channel, and which reference is returned |
| THB 1,000 reaches the replacement request | How the revised order is matched and released for fulfilment |
| THB 1,200 reaches the original request | How the unexpected receipt is identified and reviewed |
| Both requests receive payment | How the THB 2,200 total is detected without fulfilling the order twice |
In the last case, the business has THB 1,200 beyond the revised purchase amount to resolve. Do not silently treat it as additional sales. Agree who investigates, what refund operation is available and how its outcome reconnects to the original receipt. Refund timing and eligibility require confirmation with the PSP.
Confirm the receipt independently of the customer screen
KBank separately lists payment-notification callbacks, payment inquiry, void and settlement operations. Their separation is a useful reminder to request evidence for each stage; a QR-generation response is not a payment result. KBank: QR API service functions
Ask how your system verifies a notification, retrieves a result when notification is delayed, and avoids recording the same receipt twice. Finance should be able to connect the order reference, received amount, transaction identifier and account entry. A customer's screenshot can help an investigation, but should not be the sole trigger for fulfilment.
Also distinguish cancelling a payment request from returning money already received. Ask for a report covering both successful payments and exceptions, with fees and the amount available to the merchant explained separately.
THB payouts and overseas customers need separate checks
For business payouts, provide recipient types, payment purposes, amounts and frequency. Confirm supported beneficiary details, funding requirements, limits, approval controls and item-level completion evidence. A working collection demonstration does not establish those capabilities.
For international customers, the BOT describes cross-border QR purchases and cross-border funds transfers as separate use cases, with participating applications and institutions. Confirm the particular customer application and merchant acceptance arrangement. Overseas customer acceptance does not establish your company's onboarding eligibility or settlement to an overseas account. BOT: cross-border payment linkages
Focus your Thailand provider shortlist
PayStar's 14 September 2026 snapshot contains 14 unique recorded payment offers associated only with Thailand: eight collections and six payouts. All 14 have a THB association. These are offer records, not counts of independent PSPs, active integrations or approved routes. Separate currency and method links do not prove every combination; current availability and merchant eligibility need confirmation.
PayStar Discovery helps research and qualify options around your business and payment requirements. The merchant selects and contracts directly with the PSP; that provider handles processing and settlement under its agreement.
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