How It Works

On Mobile

The buyer selects Mobile Banking at checkout and chooses their bank.
They are automatically deep-linked into their bank’s mobile app.
The buyer authenticates and approves the payment inside the app.
Once approved, the buyer is returned to the merchant’s app or browser.

On Desktop

The buyer selects Mobile Banking at checkout and chooses their bank (KTB, KMA, KPlus, or SCB).
A QR code is displayed on the checkout page.
The buyer scans the QR code using their phone’s camera or QR scanner.
The bank’s mobile app opens on their phone, where they authenticate and approve the payment.
Once approved, the desktop page updates to confirm the payment.

Payment Expiry

The expiry timer starts once the payment attempt is made. The expiry time applies to both the QR code and deep-link flows.

Bank	Expiry Time
KPlus (KBank)	10 minutes
SCB	15 minutes
KMA (Krungthai)	15 minutes
KTB (Krungthai)	15 minutes

If the session expires, the buyer will need to restart the payment.

Integrating on your website / application

Step 1: Create a payin

Tazapay uses a payin object to represent your intent to collect a payment from your customer. The payin object tracks state changes from transaction creation to payment completion via mobile banking.
Create a payin on your server with an amount, invoice_currency THB and a transaction_description using the create payin API A payin is created with the status requires_payment_method.

Sample cURL

curl --request POST \
     --url https://service-sandbox.tazapay.com/v3/payin \
     --header 'accept: application/json' \
     --header 'authorization: Basic xxxxxxxXXXXxxxxxxxxxxxxxxxxx' \
     --header 'content-type: application/json' \
     --data '
{
  "invoice_currency": "THB",
  "amount": 10000,
  "transaction_description": "Test",
}
'

Step 2: Confirm a payin

Confirm the payin created in step 1 using the confirm payin API. Upon confirmation of the payin, a redirect URL is generated to redirect the customer. The status of the payin moves to requires_action Refer the below for the fields to be passed in payment_method_details

Field	Type	Mandatory (Y/N)	Description
type	string	Y	`mobilebanking_thb`
bank_name	string	Y	Bank code for the customer’s mobile banking app. One of: `ktb`, `kma`, `kplus`, `scb`

The following top-level fields are also required for mobilebanking_thb:

Field	Type	Mandatory (Y/N)	Description
mobile_number	string	Y	Customer’s mobile number in thai mobile-no format (e.g. `+664673826278`)
session_id	string	Y	Session ID retrieved from the Risk SDK

Sample cURL

curl --request POST \
     --url https://service-sandbox.tazapay.com/v3/payin/pay_cttprok2ukmk385sbfm0/confirm \
     --header 'accept: application/json' \
     --header 'authorization: Basic xxxxxxxXXXXxxxxxxxxxxxxxxxxx' \
     --header 'content-type: application/json' \
     --data '
{
  "customer_details": {
    "name": "Andrea Lark",
    "email": "andrea@example.com",
    "country": "TH"
  },
  "payment_method_details": {
    "type": "mobilebanking_thb",
    "bank_name": "ktb",
  },
  "mobile_number" : "+664673826278",
  "session_id": "<session_id>"
}
'

Combining Steps 1 and 2 into a single step

Instead of making 2 API calls, you can also combine steps 1 and 2 into a single API call. To do so, pass the parameters in both the create payin and confirm payin endpoints to the create payin API. Also, pass the following field and set the field to ‘true’

Field	type	Mandatory (Y/N)	Description
confirm	boolean	Y	To confirm the payin along with creation

Sample cURL

curl --request POST \
     --url https://service-sandbox.tazapay.com/v3/payin \
     --header 'accept: application/json' \
     --header 'authorization: Basic xxxxxxxXXXXxxxxxxxxxxxxxxxxx' \
     --header 'content-type: application/json' \
     --data '
{
  "customer_details": {
    "name": "Andrea Lark",
    "email": "andrea@example.com",
    "country": "TH"
  },
  "confirm": true,
  "invoice_currency": "THB",
  "amount": 10000,
  "transaction_description": "test",
  "payment_method_details": {
    "type": "mobilebanking_thb",
    "bank_name": "ktb",
  },
  "mobile_number": "+664673826278",
  "session_id": "<session_id>"
}
'

Step 3: Handle the confirm payin response

The confirm payin response differs based on the customer’s device type. Tazapay determines the device from the context of the request.

Desktop

For desktop sessions, the response includes a qr_code field inside latest_payment_attempt_data. You must render this QR code on your checkout page. The customer then scans the QR code using their mobile banking app to complete the payment.

{
  "status": "success",
  "data": {
    ...
    "latest_payment_attempt_data": {
      "expires_at": "2025-01-15T10:35:05Z",
      "qr_code": "<base64-encoded-qr-image-or-qr-string>"
    },
    "status": "requires_action"
  }
}

Render the latest_payment_attempt_data.qr_code value as a QR code image on your checkout page. The customer scans this with their mobile banking app.

Mobile

For mobile sessions, the response includes a deep_link field inside latest_payment_attempt_data. Since the customer has already provided their mobile number, you only need to redirect them to this deep link. It takes the customer directly into their mobile banking app to authorise and complete the payment.

{
  "status": "success",
  "data": {
    ...
    "latest_payment_attempt_data": {
      "expires_at": "2025-01-15T10:35:05Z",
      "deep_link": "bankapp://pay?ref=MIykUpsyrxRgjWOu1U5csBzZOqk9RaNPzDhMMDErEgc="
    },
    "status": "requires_action"
  }
}

Redirect the customer to latest_payment_attempt_data.deep_link to take them directly into their mobile banking app to complete the payment.

Full response example

{
  "status": "success",
  "message": "",
  "data": {
    "amount": 10000,
    "amount_paid": 0,
    "billing_details": {
      "address": null,
      "label": "",
      "name": "",
      "phone": null
    },
    "cancel_url": "",
    "cancelled_at": null,
    "client_token": "MIykUpsyrxRgjWOu1U5csBzZOqk9RaNPzDhMMDErEgc=",
    "confirm": true,
    "created_at": "2025-01-15T10:27:09.896074Z",
    "customer": "cus_cu3osb970g0h95qr5c00",
    "customer_details": {
      "country": "TH",
      "email": "andrea@example.com",
      "name": "Andrea Lark",
      "phone": {
        "calling_code": "",
        "number": ""
      }
    },
    "form": "",
    "holding_currency": "USD",
    "id": "pay_cu3oqvd3t210o3k432k0",
    "invoice_currency": "THB",
    "items": [],
    "latest_payment_attempt": "pat_cu3osbd3t210o3k434f0",
    "latest_payment_attempt_data": {
      "expires_at": "2025-01-15T10:35:05Z",
      "deep_link": "bankapp://pay?ref=MIykUpsyrxRgjWOu1U5csBzZOqk9RaNPzDhMMDErEgc="
    },
    "metadata": null,
    "object": "payin",
    "paid_in_excess": false,
    "partially_paid": false,
    "payment_attempts": [],
    "payment_method_details": {
      "type": "mobilebanking_thb"
    },
    "redirect_url": "https://checkout-sandbox.tazapay.com/simulate/MIykUpsyrxRgjWOu1U5csBzZOqk9RaNPzDhMMDErEgc=/pay_cu3oqvd3t210o3k432k0/mobilebanking_thb",
    "reference_id": "",
    "shipping_details": {
      "address": null,
      "label": "",
      "name": "",
      "phone": null
    },
    "statement_descriptor": "",
    "status": "requires_action",
    "status_description": "",
    "success_url": "",
    "transaction_data": [],
    "transaction_description": "test",
    "transaction_documents": [],
    "webhook_url": ""
  }
}

Step 4: Handle post-payment events

Tazapay sends a payin.succeeded event as soon as the funds are received from the customer. Tazapay sends these events to the endpoint configured from your dashboard. You can receive these events and run actions (for example, sending an order confirmation email to your customers, logging the sale in a database, starting a shipping workflow, etc.) If the payment is not made by the customer and the URL expires, Tazapay sends a payment_attempt.failed event. To generate a new URL, confirm the payin again using Step 2.

Event	Description	Next Steps
payin.succeeded	The customer paid before 30 days	Fulfill the goods or services that the customer purchased
payment_attempt.failed	The customer did not pay, and the URL expired	Allow the customer to generate a new URL or complete the payment via another payment method

Test the Integration

Simulating success

Click on Simulate Success CTA on the redirect_url. You will receive a payin.succeeded event.

Simulating Failure / Expiry

Click on Simulate Expire CTA on the redirect_url. You will receive a payment_attempt.failed event.

Integrating Refunds

You can refund a transaction in two ways - using the dashboard or using Refund API. Mobile banking supports partial refunds. Specify the amount (lesser than the invoice amount of the payin) for the refund before initiating.

Refunding using dashboard

Refer to this guide: https://support.tazapay.com/how-do-i-request-a-refund-from-my-dashboard

Refund using API

Sample cURL

curl --request POST \
     --url https://service-sandbox.tazapay.com/v3/refund \
     --header 'accept: application/json' \
     --header 'authorization: Basic xxxxxxxXXXXxxxxxxxxxxxxxxxxx' \
     --header 'content-type: application/json' \
     --data '
{
  "payin": "pay_cmiiaamaq0pbt3fkadm0",
  "amount": 5000,
  "currency": "THB",
  "reason": "Customer Return",
  }
'

For full refund, specifying the amount and currency is not required to initiate a refund.

​How It Works

​On Mobile

​On Desktop

​Payment Expiry

​Integrating on your website / application

​Step 1: Create a payin

​Sample cURL

​Step 2: Confirm a payin

​Sample cURL

​Combining Steps 1 and 2 into a single step

​Sample cURL

​Step 3: Handle the confirm payin response

​Desktop

​Mobile

​Full response example

​Step 4: Handle post-payment events

​Test the Integration

​Simulating success

​Simulating Failure / Expiry

​Integrating Refunds

​Refunding using dashboard

​Refund using API

How It Works

On Mobile

On Desktop

Payment Expiry

Integrating on your website / application

Step 1: Create a payin

Sample cURL

Step 2: Confirm a payin

Sample cURL

Combining Steps 1 and 2 into a single step

Sample cURL

Step 3: Handle the confirm payin response

Desktop

Mobile

Full response example

Step 4: Handle post-payment events

Test the Integration

Simulating success

Simulating Failure / Expiry

Integrating Refunds

Refunding using dashboard

Refund using API