# Maximum Limit Exceeded
source: https://developer.mastercard.com/open-finance-au/documentation/errors/request/max-limit-exceeded/index.md

This error occurs when calls made have reached the maximum limit allowed by a financial institution in a given time frame.

## 977 {#977}

|            Title            |                                                                                                                                   Details                                                                                                                                    |
|-----------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **Aggregation Status Code** | 977                                                                                                                                                                                                                                                                          |
| **Remediation Category**    | Report or Escalate for Investigation                                                                                                                                                                                                                                         |
| **HTTP Status**             | 500                                                                                                                                                                                                                                                                          |
| **Error Message**           | Service has reached the maximum limit or expired. ​                                                                                                                                                                                                                          |
| **Common Causes**           | This error happens when the number of requests to a particular financial institution exceeds the set rate limit.                                                                                                                                                             |
| **Troubleshooting Steps**   | Review all requests made with your API credentials. This can help you identify if you're sending an excessive number of requests to a particular financial institution. Ensure that you're only making necessary API calls and that you're efficiently using each request. ​ |
| **Retriable by End User**   | No.                                                                                                                                                                                                                                                                          |
| **Access to Latest Data**   | You cannot access the latest data for this account until the issue is resolved.                                                                                                                                                                                              |

[Full Error List](https://developer.mastercard.com/open-finance-au/documentation/errors/error-list/index.md)

## 44000 {#44000}

|            Title            |                                                                                    Details                                                                                     |
|-----------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **Aggregation Status Code** | 44000                                                                                                                                                                          |
| **Remediation Category**    | Retry Later                                                                                                                                                                    |
| **HTTP Status**             | 202                                                                                                                                                                            |
| **Error Message**           | Invalid App key.                                                                                                                                                               |
| **Common Causes**           | This error indicates that you have reached your maximum API usage plan limit. The number of requests you have made has exceeded the threshold set for your current usage plan. |
| **Troubleshooting Steps**   | Review your usage plan to understand rate limits. Reach out to your support team if you require higher rate limit than what's available to you. ​                              |
| **Retriable by End User**   | No.                                                                                                                                                                            |
| **Access to Latest Data**   | You cannot access the latest data for this account until the issue is resolved.                                                                                                |

[Full Error List](https://developer.mastercard.com/open-finance-au/documentation/errors/error-list/index.md#request-errors)

## 44002 {#44002}

|            Title            |                                 Details                                 |
|-----------------------------|-------------------------------------------------------------------------|
| **Aggregation Status Code** | 44002                                                                   |
| **Remediation Category**    | Retry Later                                                             |
| **HTTP Status**             | 202                                                                     |
| **Error Message**           | Aggregation service is temporarily unavailable. Please try again later. |
| **Common Causes**           |                                                                         |
| **Troubleshooting Steps**   |                                                                         |
| **Retriable by End User**   |                                                                         |
| **Access to Latest Data**   |                                                                         |

[Full Error List](https://developer.mastercard.com/open-finance-au/documentation/errors/error-list/index.md#request-errors)