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Payment cancellation (refund)
Learn how to cancel a payment using the i'mport payment cancel API.
Request a refund to the server with the required refund information. In the case of virtual account refund, you need to specify additional parameters for the refund deposit account information. The following example requests a refund with the required refund information.
HTML
React.js
client-side
<button onclick="cancelPay()">Request Refund</button>
<script
src="https://code.jquery.com/jquery-3.3.1.min.js"
integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8="
crossorigin="anonymous"></script><!-- jQuery CDN --->
<script>
function cancelPay() {
jQuery.ajax({
"url": "{URL to receive refund request}", // Example: http://www.myservice.com/payments/cancel
"type": "POST",
"contentType": "application/json",
"data": JSON.stringify({
"merchant_uid": "{Order ID}", // Example: ORD20180131-0000011
"cancel_request_amount": 2000, // Refund amount
"reason": "Testing payment refund" // Reason for the refund
"refund_holder": "Jone Doe", // [required for virtual account refund] refund account holder's name
"refund_bank": "88" // [required for virtual account refund] refund account bank code (e.g. Shinhan Bank is 88 for KG Inicis)
"refund_account": "56211105948400" // [required for virtual account refund] refund account number
}),
"dataType": "json"
});
}
</script>
Sample refund button
client-side
class CancelPay extends React.Component {
cancelPay = () => {
axios({
url: "{URL to receive refund request}", // Example: http://www.myservice.com/payments/cancel
method: "POST",
headers: {
"Content-Type": "application/json,
},
data: {
merchant_uid: "mid_" + new Date().getTime(), // Order ID
cancel_request_amount: 2000, // Refund amount
reason: "Refund for test payment" // Reason for the refund
refund_holder: "Jone Doe", // [required for virtual account refund] refund account holder's name
refund_bank: "88" // [required for virtual account refund] refund account bank code (e.g. Shinhan Bank is 88 for KG Inicis)
refund_account: "56211105948400" // [required for virtual account refund] refund account number
}
});
}
...
render() {
return <button onClick={this.cancelPay}>Request Refund</button>;
}
}
Assume that there is a
Payments
table that stores payment information as follows:server-side
/* ... model/payments.js ... */
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
...
var PaymentsSchema = new Schema({
imp_uid: String, // i'mport unique ID (unique key for refund)
merchant_uid: String, // order ID (used to query payment information)
amount: { type: Number, default: 0 }, // Payment amount (for calculating refundable amount)
cancel_amount: { type: Number, default: 0 }, // Total amount refunded (for calculating refundable amount)
...
});
...
module.exports = mongoose.model('Payments', PaymentsSchema);
Query the payment information of the order from the
Payments
table using the order ID (merchant_uid
) received from the client.server-side
/* ... Omitted ... */
var Payments = require('./models/payments');
app.post('/payments/cancel', async (req, res, next) => {
try {
/* Get access token */
/* ... Omitted ... */
/* Get payment information */
const { body } = req;
const { merchant_uid } = body; // Order ID from the client
Payments.find({ merchant_uid }, async function(err, payment) {
if (err) {
return res.json(err);
}
const paymentData = payment[0]; // Save payment information
/* Call i'mport REST API to request refund */
...
});
} catch (error) {
res.status(400).send(error);
}
});
To request a refund, you must first get a REST API access token. Use the
access token
to call the i'mport cancel API to request a refund.Note - Refunding mobile micropayments
- If a refund is requested on a different month from when the payment is made, a full refund is not allowed. For example, a payment made on January 31st is not refundable on February 1st.
Setting parameters for refund request:
Refundunique key
Setimp_uid
ormerchant_uid
as theunique key
that identifies the transaction to be refunded. The value ofimp_uid
takes precedence, and if an invalidimp_uid
value is entered, the refund request will fail regardless of themerchant_uid
value.
Refund amount (amount
)Enter the refund amount. If amount is not specified, the full amount will be refunded.
Refundable amount (checksum
)Enter the refundable amount. For example, thechecksum
of a product that costs 10,000 won is 10,000. If this payment has been partially refunded for 1,000 won in the past, thechecksum
is 9000 for the subsequent refund request. Thechecksum
is used to check whether the refundable amount is the same between the merchant server and the i'mport server. If they do not match, the refund request will fail. If thechecksum
is not specified, the verification is not performed.
Reason for entering checksum
checksum
is not required, but it is recommended for comparing the refundable amount between the merchant server and the i'mport server.For example, consider the case when a partial refund request of 1,000 won for a 10,000 won payment was completed on the i'mport server, but not on the merchant server due to a server or database error. In this case, the checksum of the i'mport server is changed to 9000, but that of the merchant server remains 10,000.
If you attempt to make a refund request with
checksum(10000)
, the request will fail because the value does not match the checksum(9000)
of the i'mport server.Node.js
/* ... Omitted ... */
app.post('/payments/cancel', async (req, res, next) => {
try {
/* Get access token */
/* ... Omitted ... */
/* Get payment information */
const { body } = req;
const { merchant_uid, reason, cancel_request_amount } = body; // Order ID from the client, reason for refund, refund amount
Payments.find({ merchant_uid }, async function(err, payment) {
/* ... Omitted ... */
const paymentData = payment[0]; // Save payment information
const { imp_uid, amount, cancel_amount } = paymentData; // Get imp_uid, amount(paid amount), cancel_amount(total refund amount) from payment information
const cancelableAmount = amount - cancel_amount; // Refundable amount (= paid amount - total refund amount)
if (cancelableAmount <= 0) { // If refundable amount is 0
return res.status(400).json({ message: "This order has already been fully refunded." });
}
...
/* Call i'mport REST API to request refund */
const getCancelData = await axios({
url: "{URL to receive refund request}", // Example: http://www.myservice.com/payments/cancel
method: "post",
headers: {
"Content-Type": "application/json",
"Authorization": access_token // Access token from i'mport server
},
data: {
reason, // Reason for refund from client
imp_uid, // Unique key for refund
amount: cancel_request_amount, // Requested refund amount
checksum: cancelableAmount // [Recommended] refundable amount
}
});
const { response } = getCancelData.data; // Refund result
/* Save refund result */
...
});
} catch (error) {
res.status(400).send(error);
}
});
Node.js
/* ... Omitted ... */
app.post('/payments/cancel', async (req, res, next) => {
try {
/* Get access token */
/* ... Omitted ... */
/* Get payment information */
Payments.find({ merchant_uid }, async function(err, payment) {
/* ... Omitted ... */
/* Call i'mport REST API to request refund */
/* ... Omitted ... */
const { response } = getCancelData.data; // Refund result
/* Save refund result */
const { merchant_uid } = response; // Get order info from refund response
Payments.findOneAndUpdate({ merchant_uid }, response, { new: true }, function(err, payment) { // Get and update payment information for the order
if (err) {
return res.json(err);
}
res.json(payment); // Return refund result to the client
});
});
} catch (error) {
res.status(400).send(error);
}
});
Note - When cancelling a payment
Even if a response code of 200 (OK) is returned for the REST API (POST https://api.iamport.kr/payments/cancel) request, a non-zero code in the response body means that the refund has failed. You can check the reason for the failure in the message of the body.
Add the client-side logic to handle the response from the server as follows:
HTML
React.js
client-side
<button onclick="cancelPay()">Request Refund</button>
<script
src="https://code.jquery.com/jquery-3.3.1.min.js"
integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8="
crossorigin="anonymous"></script><!-- jQuery CDN --->
<script>
function cancelPay() {
jQuery.ajax({
/* ... Omitted ... */
}).done(function(result) { // If refund is successful
alert("Refund successful");
}).fail(function(error) { // If refund fails
alert("Refund failed");
});
}
</script>
client-side
class CancelPay extends React.Component {
cancelPay = () => {
axios({
/* ... Omitted ... */
}).then(response => { // If refund is successful
alert("Refund successful");
}).catch(error => { // If refund fails
alert("Refund failed");
});
}
...
render() {
return <button onClick={this.cancelPay}>Request Refund</button>;
}
}
Last modified 1yr ago