5. Refund interface

This XML-interface enables Merchant to cancel transaction and return funds to Client. This kind of refund is possible to process up to 01.00 o’clock next day after payment. This interface also used for returning funds out of proceeds of future earnings if this is foreseen by the contract.

Action - https://api.paymaster.ua/merchants/refund

Method - POST

XML-request format:

<Command>
    <LMI_MERCHANT_ID></LMI_MERCHANT_ID>
    <LMI_SYS_PAYMENT_ID></LMI_SYS_PAYMENT_ID>
    <RefundId></RefundId>
    <ActionAmount></ActionAmount>
    <RefundAmount></RefundAmount>
    <LMI_HASH></LMI_HASH>
</Command>

Name	XML-format	Description
Merchant ID	LMI_MERCHANT_ID	Merchant’s POS ID which received a payment from Client.
Internal payment number in PayMaster system	LMI_SYS_PAYMENT_ID
Unique refund request number	RefundId	Refund request number is a unique one in LMIMERCHANT_ID. It may content a letters of Roman alphabet, figures, signs “-" and "" (without inverted commas; a line can’t begin from signs). Maximum lenth of the number - 20 symbols.
Total payment amount	ActionAmount
Cancellation amount	RefundAmount	Refund amount must be less or equal to full amount of payment. Some payment systems support partial payment refunds.
Control signature	LMI_HASH	Control signature of request which is created by encoding outgoing text of XML-request with blank field LMI_HASH and blank secret key SecretKey using algorithm chosen in Merchant’s cabinet. Received signature is transferred at tag LMI_HASH. The recommended encoding algorithm is SHA256.

XML-response format:

<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Retval></Retval>
    <Retdesc></Retdesc>
    <Retdata>
        <ResultCode></ResultCode>
        <ResultMsg></ResultMsg>
    </Retdata>
</Response>

Name	XML-format	Description
Operation code of request	Retval	1 (one) – successful transaction
Description of operation code	Retdesc
Refund code	Retdata/ResultCode
Description of refund code	Retdata/ResultMsg

NOTE! Unlike other interfaces and forms, refund interface has 2 statuses (operation codes). Operation code of request (Retval) indicates successful or unsuccessful refund request, while refund result code (Retdata/ResultCode) indicates successful refunds in payment system.

In case of receiving a non-final response in field Retdata/ResultCode it’s possible to make another request with the same parameters (necessarily with the same RefundId) to get a status of the processed request.

Codes of refund operations

Code	Explanation	Final/non-final
600	Refund was successful	Final
601	Transaction not found	Final
602	Refund is possible only for successful transactions	Final
603	Refund time is over	Final
604	Invalid payment amount	Final
605	Invalid refund amount	Final
606	Refund amount cannot exceed full amount of payment	Final
607	Refund operation is being processed	Non-final
608	Transaction is already refunded	Final
609	Payment system doesn’t support refunds	Final
610	Payment system doesn’t support partial refunds	Final
618	Invalid ID refund	Final