Posting to the previous period (backposting) is allowed only if the corresponding indicator is set in the control record. This indicator is set automatically during initialization and after each change of period. However, it can sometimes be necessary to set it manually.
In the Material Master menu, choose
The initial screen appears.
Enter the company code and choose Enter .
Set the Allow posting to previous per. indicator.
Save your data.
Access Customizing for the Material Master and choose Maintain Company Codes for Materials Management .
The overview screen appears.
Set the ABp (allow backposting) indicator for each company code as required.
Save your data .