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KCP Alternative Payments

Korea Cyber Payment (KCP) is a South Korean payment services company that provides internet-based payment services to its customers. All KCP payments are processed in South Korean Won (KRW). Contact KCP for a list of supported desktop browsers and mobile devices.

Payment Methods

KCP accepts these payment methods: KakaoPay, Naver Pay, and Payco through the alternative payment service, and credit card payment, mobile billing payment, and real-time bank transfer through KCP directly.

Through the REST API, set paymentInformation.paymentType.method.name to KAKAOPAY, NAVERPAY, PAYCO, or KCP (for credit card, mobile billing, or real-time bank transfer).

Sale Workflow

This workflow describes the sequence of events that comprises a successful KCP sale transaction.

SaleCheck Statusfor a SaleMerchant sendsinitiate sale API request2Customer checks out onmerchant website and choosesKCP payment method1responds with a successfullyprocessed message + redirect URL3Merchant directscustomer to the URL4Customer completes check outusing KCP payment method and isredirected to merchant website5Merchant sendscheck status API request6Merchant confirms paymentto customer8responds with COMPLETED status 7EndCustomer GatewayMerchant
KCP Sale Workflow
  1. The customer begins to check out on the merchant's website and selects a KCP supported payment method, such as KakaoPay, Naver Pay, or Payco.
  2. The merchant sends an initiate sale API request to . The merchant can include the deviceInformation.appUrl (REST) or ap_appUrl (Simple Order) optional field to wake up the app during the payment process. For more information, see Sales.
  3. responds to the merchant with a success message and an encrypted redirect URL. For more information about the redirect URL, see Merchant Redirect URL.
  4. The merchant redirects the customer to the URL.
  5. The customer uses their KCP account to complete the payment. When the checkout is complete, the customer is redirected to the merchant website. If using KakaoPay, Naver Pay, or Payco, the app URL provided in the sale request now wakes up the merchant app when payment processing is complete.
  6. The merchant immediately sends a check status API request to . For more information, see Status Checks.
  7. responds to the merchant with a COMPLETED status when the payment is successfully processed, and the purchased goods can now be shipped. can also respond with CANCELLED (payment was cancelled by the customer; do not ship the goods), DECLINE (payment was rejected by the processor; do not ship the goods), or PENDING (payment is still in progress; do not ship the goods: send a check status request every hour until the status updates).
  8. The merchant displays a payment confirmation to the customer.

Refund Workflow

This workflow describes the sequence of events that comprises a successful KCP refund.

RefundCheck Statusfor a RefundMerchant sendsrefund API request2Customer returns purchase1responds with successfullyprocessed message3Merchant sendscheck status API request4Merchant confirms refundto customer6responds with REFUNDED status 5EndCustomer GatewayMerchant
KCP Refund Workflow
  1. The customer returns a purchase to the merchant.
  2. The merchant sends a refund API request to . For more information, see Refunds.
  3. responds to the merchant with a success message.
  4. The merchant sends a check status API request to with the request ID.
  5. responds to the merchant with a REFUNDED status. If responds with a PENDING status, the merchant sends a check status API request every hour until the status updates.
  6. The merchant displays a refund confirmation to the customer.

Merchant Redirect URL

After you initiate a sale, the processorInformation.paymentUrl (REST) or apInitiateReply_merchantURL (Simple Order) response field contains the merchant URL that redirects the customer to the KCP website.

The merchant URL consists of the KCP website address and a string of encrypted data:

ParameterDescription
KCP website (Test)https://testpay.kcp.co.kr/Pay/module/cyberSource/KCP_Gateway.jsp
KCP website (Production)https://pay.kcp.co.kr/Pay/module/cyberSource/KCP_Gateway.jsp
Encrypted dataAll the customer's payment information signed and encrypted in a string of data.

The encrypted data consists of these parameters.

AppUrl

App URL used by KCP to wake up the merchant app after payment processing is complete. Format: {a-z}://.

buyr_mail

Customer email.

buyr_name

Customer name.

buyr_tel

Customer telephone number.

comm_green_deposit_mny

Refundable deposit amount. If this field is present and the merchant ID is enabled, the payment is processed. If this field is present and the merchant ID is disabled, the payment is not processed. If this field is not present, the payment is processed regardless of whether the merchant ID is enabled.

currency

Three-digit numeric currency code used for the order. KRW: 410.

eng_flag

English-language indicator for the KCP plug-in.

escw_used

Provides the escrow option to a customer. Possible values: Y (yes) or N (no).

good_mny

Payment amount.

good_name

Product purchased by the customer.

ordr_idxx

Unique merchant-generated request ID. If it is not included, generates this request ID.

pay_method

Payment method. Possible values: 100000000000 (credit card, KakaoPay, Naver Pay, and Payco), 010000000000 (bank transfer), or 000010000000 (mobile billing).

quotaopt

Installment payment frequency for credit card payments only. Possible values: 00 to 12. Default value: 12.

ret_url

Merchant-defined URL for displaying the payment results to the customer. You can also specify this URL during merchant boarding.

signature

RSA signature and SHA-256 data hashing.

site_cd

KCP merchant ID.

site_name

Merchant brand name.

skin_indx

Payment UI skin number. Each number displays a different color of the KCP plug-in UI.

Some web browsers restrict browser URL lengths. recommends using this code when performing the redirect using client-side JavaScript to avoid issues with URL lengths:

<SCRIPT LANGUAGE='JavaScript'>    var win=window.open('','_blank');    win.location='" . $apInitiateReply->merchantURL . "';</SCRIPT>

Last published: September 29, 2026