> ## Documentation Index > Fetch the complete documentation index at: https://walletconnect-pay-docs-wcagent-webview-integration-docs.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Mark a payment as refunded > Request a full refund for a payment. Calling a second time on the same payment returns 409. ## OpenAPI ````yaml api/2026-02-18.json POST /v1/refunds openapi: 3.1.0 info: title: WalletConnect Pay API version: '2026-02-18' servers: - url: https://api.pay.walletconnect.com security: - API Key: [] - ApiKey: [] - AppId: [] tags: - name: Gateway - name: Payments - name: Refunds - name: Merchant Management - name: Settlements - name: Crypto Settlement paths: /v1/refunds: post: tags: - Refunds summary: Mark a payment as refunded description: >- Request a full refund for a payment. Calling a second time on the same payment returns 409. operationId: Refunds_create parameters: - name: Merchant-Id in: header required: true description: Merchant identifier. schema: type: string examples: - acme-store-1 - name: WCP-Version in: header required: false description: >- Optional WalletConnect Pay API version override. If omitted, the partner's pinned version is used. schema: type: string examples: - '2026-02-18' - 2026-02-19.preview requestBody: required: true content: application/json: schema: type: object properties: paymentId: type: string minLength: 1 maxLength: 64 pattern: ^pay_[A-Za-z0-9]+$ description: Payment ID to refund examples: - pay_a1a2ecc101KGF210FP7PN3BK08PZARS1CZ required: - paymentId responses: '200': description: Payment marked as refunded headers: WCP-Version: description: WalletConnect Pay API version resolved for this request. schema: type: string content: application/json: schema: type: object properties: paymentId: type: string description: Payment ID that was marked as refunded required: - paymentId example: paymentId: pay_a1a2ecc101KGF210FP7PN3BK08PZARS1CZ '400': description: Bad request content: application/json: schema: type: object properties: message: type: string description: Human-readable error message code: type: string enum: - params_validation - payment_not_succeeded - invalid_api_version - unknown_api_version - api_version_downgrade description: Machine-readable error code details: description: Additional structured error details type: object propertyNames: type: string additionalProperties: {} issues: type: array description: >- Field-level validation issues (present on validation errors) items: type: object required: - field - message properties: field: type: string message: type: string required: - message - code examples: params_validation: summary: Validation failed value: code: params_validation message: Validation failed payment_not_succeeded: summary: Payment is not in a refundable state value: code: payment_not_succeeded message: Payment is not in a refundable state invalid_api_version: summary: Invalid API version value: code: invalid_api_version message: Invalid API version unknown_api_version: summary: Unknown API version value: code: unknown_api_version message: Unknown API version api_version_downgrade: summary: Requested API version is older than the partner pin value: code: api_version_downgrade message: Requested API version is older than the partner pin '401': description: Unauthorized — missing or invalid API key, or missing merchant id content: application/json: schema: type: object properties: message: type: string description: Human-readable error message code: type: string enum: - missing_api_key - invalid_api_key - missing_merchant_id description: Machine-readable error code details: description: Additional structured error details type: object propertyNames: type: string additionalProperties: {} required: - message - code examples: missing_api_key: summary: Missing API key value: code: missing_api_key message: Missing API key invalid_api_key: summary: Invalid API key value: code: invalid_api_key message: Invalid API key missing_merchant_id: summary: Missing Merchant ID value: code: missing_merchant_id message: Missing Merchant ID '404': description: Payment not found content: application/json: schema: type: object properties: message: type: string description: Human-readable error message code: type: string const: not_found description: Machine-readable error code details: description: Additional structured error details type: object propertyNames: type: string additionalProperties: {} required: - message - code examples: not_found: summary: Not Found value: code: not_found message: Not Found '409': description: Payment is already refunded content: application/json: schema: type: object properties: message: type: string description: Human-readable error message code: type: string const: already_refunded description: Machine-readable error code details: description: Additional structured error details type: object propertyNames: type: string additionalProperties: {} required: - message - code examples: already_refunded: summary: Payment is already refunded value: code: already_refunded message: Payment is already refunded '500': description: Internal error content: application/json: schema: type: object properties: message: type: string description: Human-readable error message code: type: string const: internal_error description: Machine-readable error code details: description: Additional structured error details type: object propertyNames: type: string additionalProperties: {} required: - message - code examples: internal_error: summary: Internal Server Error value: code: internal_error message: Internal Server Error '502': description: Bad gateway content: application/json: schema: type: object properties: message: type: string description: Human-readable error message code: type: string const: bad_gateway description: Machine-readable error code details: description: Additional structured error details type: object propertyNames: type: string additionalProperties: {} required: - message - code examples: bad_gateway: summary: Bad Gateway value: code: bad_gateway message: Bad Gateway components: securitySchemes: API Key: type: apiKey in: header name: Api-Key ApiKey: type: apiKey in: header name: Api-Key description: Private API key for wallet authentication AppId: type: apiKey in: header name: App-Id description: >- Public App ID for wallet authentication. When using this auth mode, the Client-Id header is also required. ````