# Historical Data Sharing
source: https://developer.mastercard.com/open-finance-us/documentation/products/pay/psi-tools/historical-data-sharing/index.md

To support ongoing model improvement and ensure alignment with evolving
fraud trends, partners are required to share historical transaction data
with us securely via [Feedback Loop](https://developer.mastercard.com/open-finance-us/documentation/products/pay/feedback-loop/index.md).

Whether using the PSI [FCRA](https://developer.mastercard.com/open-finance-us/documentation/products/pay/psi-tools/psi-fcra/index.md) or [Non-FCRA](https://developer.mastercard.com/open-finance-us/documentation/products/pay/psi-tools/psi/index.md) endpoints, this data is
essential for evaluating and fine-tuning model performance.
Warning: To enable data sharing, you must ensure you **store the required fields in
your own systems** so that they can be provided to us via Feedback Loop.

The following fields are required when submitting historical data to Feedback Loop and must be uploaded as a CSV file. See the Feedback Loop [Submission Format](https://developer.mastercard.com/open-finance-us/documentation/products/pay/feedback-loop/index.md#submission-format) documentation for full details.

|     Field Name     | Data Type |                        Description                         | Required |                             Notes                             |
|--------------------|-----------|------------------------------------------------------------|----------|---------------------------------------------------------------|
| `partnerId`        | integer   | Production partner ID provided by Mastercard               | Y        | Must exist in system                                          |
| `customerId`       | integer   | Customer ID provided by Mastercard                         | Y        | Must exist in system                                          |
| `payReqId`         | string    | ID of the payment transaction this feedback relates to     | Y        | Use payment request ID (`payReqId`) from earlier PSI response |
| `paymentId`        | string    | Partner-provided identifier to track/update payment status | Y        | Helps correlate multiple submissions (e.g. retries)           |
| `settled`          | string    | Indicates whether the transaction settled                  | Y        | Values: `Y` or `N`                                            |
| `initiationAmount` | decimal   | Value of the transaction                                   | Y        | Digits or decimal                                             |
| `initiationDate`   | string    | Date the transaction was initiated                         | Y        | Provide actual initiation timestamp                           |
| `settledDate`      | string    | Date the transaction settled                               | Y        | Leave blank if `settled = N`                                  |
| `returnDate`       | string    | Date the transaction was returned (yyyy-mm-dd)             | Y        | Leave blank if `settled = Y`                                  |
| `returnReason`     | string    | Reason the transaction was returned (e.g. ACH return code) | Y        | Leave blank if `settled = Y`                                  |