How To Fix M3565 - With this material type, ext. material no. must not contain only numbers

M3565 - Overview

• Message type: E = Error

• Message class: M3 - Material Master

• Message number: 565

• Message text: With this material type, ext. material no. must not contain only numbers

What causes this issue?

You have entered a material number that consists only of numbers.
However, the material type that you have chosen has been set up in
customizing in such a way that external numbers are assigned without
being checked. A purely numerical material number is not allowed for
this material type.

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

Error message extract from SAP system. Copyright SAP SE.

M3565 - Details

• The SAP error message M3565 indicates that there is an issue with the external material number (also known as the external material ID) for a specific material type. The error occurs when the external material number consists solely of numeric characters, which is not allowed for certain material types in SAP.
  
  Cause:
  The primary cause of this error is that the external material number you are trying to enter or use is composed entirely of digits (0-9). SAP has specific rules for different material types, and for some material types, the external material number must include alphabetic characters or special characters in addition to numbers.
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Modify the External Material Number: Change the external material number to include at least one alphabetic character or special character. For example, instead of using "123456", you could use "ABC123456" or "123-456".
  
  
  Check Material Type Configuration: If you have access