---
title: "Refund a transaction from the POS"
url: "https://docs.adyen.com/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/cancel-or-refund-a-transaction-jni/refund-a-transaction-from-the-pos-jni"
source_url: "https://docs.adyen.com/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/cancel-or-refund-a-transaction-jni/refund-a-transaction-from-the-pos-jni.md"
canonical: "https://docs.adyen.com/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/cancel-or-refund-a-transaction-jni/refund-a-transaction-from-the-pos-jni"
last_modified: "2026-05-25T12:55:00+02:00"
language: "en"
---

# Refund a transaction from the POS

[View source](/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/cancel-or-refund-a-transaction-jni/refund-a-transaction-from-the-pos-jni.md)

## Class

| Name          | Description                                                                                                                           |
| ------------- | ------------------------------------------------------------------------------------------------------------------------------------- |
| `MerchantPos` | Extends `AdyenPos`. Class used to implement all payment platform functionality. Implements all functions that do not involve the PED. |

## Method

| Name                  | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| --------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `cancelOrRefundAtPsp` | Start a cancel or refund. If a `pspReference` has been generated, pass this as a reference for the transaction. Otherwise, provide the `tenderReference`.This method returns an immediate response of type `LibraryResult`. Check if this result is "OK", before continuing the operation. If the `LibraryResult` value is not "OK", the system will not return the related callback with the asynchronous result. See [here](/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/process-a-basic-transaction-jni/handle-and-extract-data-from-callbacks-jni) for more on extracting data from an event or callback. |

## Tender Parameter

| Name     | Type   | Required                                                                                    | Description            |
| -------- | ------ | ------------------------------------------------------------------------------------------- | ---------------------- |
| `tender` | Tender | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Represents the tender. |

## Attributes

| Name                | Type   | Required                                                                                    | Definition                                                                                                                                            |
| ------------------- | ------ | ------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------- |
| `merchantAccount`   | String | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | The `merchantAccount` account to receive the money.                                                                                                   |
| `merchantReference` | String | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | The transaction reference provided by the Merchant (reported in the Adyen payments platform).                                                         |
| `pspReference`      | String | ![-x-](/user/data/smileys/emoji/x.png "-x-")                                                | The reference provided by the Adyen PSP (reported in the Adyen payments platform). Use the PSP reference to identify the transaction to be cancelled. |
| `tenderReference`   | String | ![-x-](/user/data/smileys/emoji/x.png "-x-")                                                | Tender reference provided by the library if there is no connection to the PSP. Use the Tender reference to identify the transaction to be cancelled.  |
| `terminalId`        | String | ![-x-](/user/data/smileys/emoji/x.png "-x-")                                                | The PED to process the transaction on.                                                                                                                |

## Callback

| Name                           | Description                               |
| ------------------------------ | ----------------------------------------- |
|  `cancelOrRefundAtPspCallback` | Returns the result of creating the tender |

## Callback Response Attributes

| Name              | Description                                                                                        |
| ----------------- | -------------------------------------------------------------------------------------------------- |
| `additionalData`  | Adyen returns the `additionalData` object, a generic container that can hold extra response fields |
| `tenderReference` | Reference the PED provides for the transaction, used in reporting on the Adyen payments platform.  |
| `tenderState`     | Transaction state                                                                                  |
| `adyenResult`     | Transaction result details                                                                         |

## Determine the current and final tender state

Adyen provides a method to determine the current, or final, tender state. For more information, see [Determine the current and final tender state - JNI](/point-of-sale/classic-library-deprecation/classic-library-integrations/java-native-interface-integration/key-steps-jni/process-a-basic-transaction-jni/determine-the-current-and-final-tender-state-jni).