Non-breaking API update: New response field for transaction callbacks (product_name)

Effective date: 16 March 2026

Overview

We're adding a new field to the transaction callback payload to include the product name alongside the existing product code. This is an additive, backward-compatible change. No request parameters, status codes, or existing callback fields are affected.

Callback methods impacted

• POST callback
• GET callback

What's changing

New field in the callback payload under data:

{
  "data": {
    "product": "CELCOM",
    "productName": "Celcom Prepaid",
    ...
  }
}

productName (string): The human-readable display name for the product associated with the transaction. This field already exists in the POST /v2/topup response and will now also be included in the callback payload.

Backward compatibility

• Non-breaking; existing fields and their formats are unchanged.
• productName is additive only. Callbacks that previously parsed will continue to parse.
• If you use strict JSON schema/model validation, update your models to include productName or configure them to ignore unknown properties.

Actions for integrators

• No action required to maintain existing functionality.
• Optional: You can now use productName from the callback payload directly to display product names in your callback-driven flows, eliminating the need to maintain a separate product code-to-name mapping.

Should you require any further assistance or additional information, please do not hesitate to reach out to us via email at support@iimmpact.com.