How To Fix W0120 - One-time customer is maintained, but ID allowing 1x customers not set

W0120 - Overview

• Message type: E = Error

• Message class: W0 - Customizing - ISR

• Message number: 120

• Message text: One-time customer is maintained, but ID allowing 1x customers not set

What causes this issue?

You entered a one-time customer number but did not select the indicator
allowing one-time customers.

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?

Set the indicator allowing one-time customers or delete the
<DS:GLOS.3526BFC5AFAB52B9E10000009B38F974>one-time customer number</>.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message W0120 - One-time customer is maintained, but ID allowing 1x customers not set ?

  Certainly! Here's a detailed explanation for the SAP error message:
  
  SAP Error Message:
  W0120 - One-time customer is maintained, but ID allowing 1x customers not set
  
  
  Cause:
  This warning message occurs when a customer master record is maintained as a one-time customer (i.e., a customer that is used only once, typically for ad-hoc or infrequent transactions), but the system settings or configuration do not allow the use of one-time customers because the relevant ID or flag enabling one-time customers is not set.
  In SAP, one-time customers are special customer master records that are used for occasional customers without creating a full customer master record. To use one-time customers, certain configuration settings must be enabled.
  
  Explanation:
  
  The customer master record has the "One-time customer" indicator set.
  However, the system configuration (usually in the sales area or customer master settings) does not have the ID allowing one-time customers activated.
  This inconsistency triggers the warning message W0120.
  
  
  
  Solution:
  
  
  Check the Customer Master Record:
  
  Verify if