# Code and Formats
source: https://developer.mastercard.com/account-catalog-services/documentation/code-and-formats/index.md

The error codes returned will depend on which API generated the error and at what point the request failed. Error messages are in one of the following formats:

* **Mastercard Gateway Error Messages**: Returned from the gateway and typically occur when OAuth 1.0a authentication fails.
* **Account Catalog Services API Error Messages**: Returned from the Account Catalog Services application and typically occur for incorrect input errors.

## Mastercard Gateway Error Messages {#mastercard-gateway-error-messages}

Under certain conditions, you might receive errors from our API gateway. New error codes can be added at any time. For a current and full listing of all error codes that can be triggered by the Mastercard API Gateway, refer to [Gateway Error Codes](https://developer.mastercard.com/platform/documentation/security-and-authentication/gateway-error-codes/).

## Mastercard Account Catalog Services {#mastercard-account-catalog-services}

For a current and full listing of all rejected error codes that can be triggered by the Account Catalog Services Platform, refer to the following documents:

* [Account-Catalog-Services-Reject-Codes.pdf](https://static.developer.mastercard.com/content/account-catalog-services/uploads/Account-Catalog-Services-Reject-Codes.pdf) (306KB).
* ALM Manual for domain specific reject code.   

New Reject Response and Error Reason Codes have been created in support of the API processing. An API response (or an object within the response) contains the elements `errorCode` and `errorDescription` as defined in the Error Reason Codes.

### Error Response Code for Account Catalog Services API and Detail Response API {#error-response-code-for-account-catalog-services-api-and-detail-response-api}

| **Reason Code** |                                          **Description**                                           |          **Message**           |                                                                                                                              **Resolution Tips**                                                                                                                              |
|-----------------|----------------------------------------------------------------------------------------------------|--------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| R0000371        | The request ID provided in the header is a duplicate and used on a previous submission.            | Acknowledgement Error Response | Generate a new request ID and provide in the header. Previous request ID should not be used.                                                                                                                                                                                  |
| R0000370        | The request ID provided in the header is required and must be present.                             | Acknowledgement Error Response | Check if the request ID is provided in the header, if not then add a unique request ID.                                                                                                                                                                                       |
| R0000372        | The authorization ID has not been approved or provisioned to the Company Identifier of the issuer. | Acknowledgement Error Response | The authorization ID is provided in the header and contains the consumer key and ClientID. The consumer key provided at the time of project creation should be used. If access to the API is not granted or the consumer key is not generated, then contact customer support. |
| R0000373        | API request has an incorrect JSON format.                                                          | Acknowledgement Error Response | Check the JSON format of the request and correct it                                                                                                                                                                                                                           |
| R0000385        | Request not processed successfully due to system failure.                                          | Acknowledgement Error Response | If the recoverable field value of the error response is true, then retry the request or contact the customer support team.                                                                                                                                                    |