# 20001 source: https://developer.mastercard.com/open-finance-us/documentation/errors/error-codes/20001/index.md This error occurs when the account number is not found. | Title | Details | |-------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | **Error Code** | 20001 | | **Remediation Category** | Verify Account or Data State | | **HTTP Status** | 500 | | **Error Type** | Request Error | | **Data Connect Alert** | No associated alert. | | **Error Message** | Real account number not found​.​ | | **Common Causes** | Ensure that you're attempting to retrieve details for a valid account number. | | **Troubleshooting Steps** | Retry with a valid account number. If issue persists, submit a [support ticket](https://developer.mastercard.com/open-finance-us/documentation/support/index.md#create-a-support-case-in-scm). | | **Data Connect Fix Eligible** | No. | | **Retriable by End User** | No. | | **Access to Latest Data** | You will be unable to retrieve the latest data until the issue is resolved. |