Void Transaction

Request a void or cancellation for a successfully completed transaction. This is primarily intended for bill payment transactions and is subject to biller approval.

TIP

For a walkthrough of the void process and webhook handling, see the Void Transaction Guide.

DANGER

AI-powered intelligence and automation are only active in production. Staging can simulate API responses for testing but won't trigger automated workflows or send email replies.

WARNING

Only use this API for transactions with a Succesful status. Not applicable for prepaid mobile top-ups, PIN-based products (e.g., game credits, gift cards), or other instant fulfillment services.

API Endpoint

POST https://api.iimmpact.com/v2/transactions/void

Request Headers

Header	Description	Required
X-Api-Key	Your API key	Yes
X-Timestamp	Unix timestamp in seconds	Yes
X-Nonce	Unique request identifier	Yes
X-Signature	HMAC-SHA256 signature (v1=...)	Yes

See API Key Authentication for how to sign your requests.

Request Body

Parameter	Type	Required	Description
refid	string	No	Your unique reference ID used when calling the Make Payment endpoint. Provide either refid or trxid
trxid	string	No	Internal IIMMPACT transaction ID. Alternative to refid — provide one or the other
user_email	array	No	Array of email addresses to include. Pass the end-user's email and any other addresses to CC
refund_type	number	Yes	Reason for the void request (see below)
refund_reason	string	No	Required only if refund_type is 3. Free-text description of the reason

INFO

At least one of refid or trxid must be provided. If both are supplied, trxid takes precedence.

Refund Types

Value	Reason
1	Incorrect Amount or Wrong Account
2	Duplicate Transaction
3	Other Reason (requires refund_reason)

Response 200

Field	Type	Description
data	object	Result
data.refid	string	The reference ID of the transaction
data.status	string	Success or Failed
data.message	string	Description of the outcome

Example Response (Success — void request submitted):

{
  "data": {
    "refid": "123456",
    "status": "Success",
    "message": "We've received your request for a status update and are in the midst of checking with the relevant service provider. We'll keep you updated on the status of your request via email."
  }
}

Example Response (Failed — duplicate request):

{
  "data": {
    "refid": "123456",
    "status": "Failed",
    "message": "Sorry, a support request has already been created for this transaction. We're working on it and will provide an update shortly."
  }
}

Example Response (Failed — transaction already refunded):

{
  "data": {
    "refid": "12345678ABCd",
    "status": "Failed",
    "message": "Sorry, Request Refund is not available for failed transactions as they are automatically refunded. Please contact us at support@iimmpact.com if you need further assistance."
  }
}

Response 400

Field	Type	Description
message	string	Error description
errors	object	Validation errors
errors.trxid	array	Transaction ID validation errors. Always keyed as trxid, even if you provided refid in the request

Example Response:

{
  "message": "The given data was invalid.",
  "errors": {
    "trxid": [
      "Invalid transaction ID or reference ID"
    ]
  }
}

Webhook Notification

When a transaction has been successfully voided and the refund processed by both the biller and IIMMPACT, a webhook notification is sent to your registered endpoint.

Key data in the webhook payload:

Field	Value	Description
status_code	53	Indicates a voided/refunded transaction
status	Failed	Status name for voided transactions

Upon receiving this webhook, your system should process the refund back to the end-user (e.g., to their original payment method or e-wallet).

Email Notifications

The registered email address of the initiating API account is always CC'd on all email correspondence sent to the end-user regarding the void request.