How To Fix 1M128 - Balancing: Key date is before posting date. Changes not allowed

SAP Error Message - Details

• Message type: E = Error

• Message class: 1M - BKK: Abschluß

• Message number: 128

• Message text: Balancing: Key date is before posting date. Changes not allowed

What causes this issue?

Since postings already exist for the new period, meaning that item
counters can already be updated, changing the key date is no longer
possible.

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?

First execute an account balancing.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message 1M128 - Balancing: Key date is before posting date. Changes not allowed ?

  The SAP error message 1M128 ("Balancing: Key date is before posting date. Changes not allowed") typically occurs in the context of financial postings, particularly when dealing with document changes or adjustments in the SAP system. This error indicates that the key date (the date you are trying to use for a transaction or adjustment) is earlier than the posting date of the document you are trying to modify. 
  Cause:
  
  Key Date vs. Posting Date: The key date is often used for determining the validity of a transaction or for reporting purposes. If the key date is set to a date that is earlier than the posting date of the document, SAP will not allow changes to be made to ensure data integrity and compliance with accounting principles.
  Document Status: The document may be in a status that does not allow changes, such as being posted to a closed period.
  Configuration Settings: Certain configuration settings in the financial module may restrict changes based on date parameters.
  
  Solution:
  
  Adjust the Key Date: Ensure that the key date you are using for the transaction or adjustment is equal to or later than the posting date of the document. You may need to change the key date in your transaction.
  Check Document Status: Verify the status of the document you are trying to change. If it is in a closed period, you may need to reopen the period or create a new document to make the necessary adjustments.
  Consult with Finance Team: If you are unsure about the implications of changing dates or documents, consult with your finance or accounting team to ensure compliance with internal policies and regulations.
  Review Configuration: If this error occurs frequently, it may be worth reviewing the configuration settings in the SAP system to see if adjustments can be made to allow for more flexibility in date handling.
  
  Related Information:
  
  SAP Notes: Check SAP Notes for any specific patches or updates related to this error message.
  Transaction Codes: Familiarize yourself with relevant transaction codes (e.g., FB02 for changing documents) and their limitations regarding date handling.
  Documentation: Review SAP documentation or user manuals related to financial postings and document management for best practices and guidelines.
  
  If the issue persists after trying the above solutions, it may be necessary to involve your SAP support team or consult with SAP directly for further assistance.