How To Fix WN201 - Please enter customer OR vendor

SAP Error Message - Details

• Message type: E = Error

• Message class: WN - Plant master data maintenance (integrated)

• Message number: 201

• Message text: Please enter customer OR vendor

What causes this issue?

You can only enter either the customer or the vendor as a parameter.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

If this message appears when you call the report, enter either the
customer or the vendor number in the selection screen.
If the message appears online, it is due to an internal error.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message WN201 - Please enter customer OR vendor ?

  The SAP error message WN201 ("Please enter customer OR vendor") typically occurs when a transaction or process requires either a customer or vendor to be specified, but neither has been provided. This error is common in various SAP modules, particularly in financial transactions, logistics, or when creating documents that involve business partners.
  Cause:
  
  Missing Input: The user did not enter a customer or vendor number in the relevant field.
  Incorrect Configuration: The system may be configured in a way that requires either a customer or vendor to be specified, but the necessary data is not available.
  Transaction Type: The transaction being executed may inherently require a customer or vendor, and the system is unable to proceed without this information.
  
  Solution:
  
  Enter Customer or Vendor: Ensure that you enter either a valid customer number or a vendor number in the appropriate field before proceeding with the transaction.
  Check Configuration: If you believe you should not be receiving this error, check the configuration settings in the relevant module to ensure that the system is set up correctly to handle the transaction.
  Data Validation: Verify that the customer or vendor you are trying to enter exists in the system and is active. You can do this by checking the master data for customers and vendors.
  Consult Documentation: Review the documentation for the specific transaction you are trying to execute to understand the requirements for customer or vendor input.
  User Training: If this error is frequently encountered by users, consider providing additional training or resources to help them understand when and how to enter customer or vendor information.
  
  Related Information:
  
  Transaction Codes: The error may occur in various transaction codes, such as those related to sales orders, purchase orders, or invoice processing.
  Business Partner Role: In newer versions of SAP (like S/4HANA), the concept of Business Partners is used, which combines customers and vendors. Ensure that the correct role is assigned to the business partner if applicable.
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message. Sometimes, specific versions of SAP may have bugs that are documented and resolved in later updates.
  
  If the issue persists after trying the above solutions, it may be beneficial to consult with your SAP support team or refer to SAP's official support channels for further assistance.