Hello, 

You must use M102 for pre-posting. If you will create M102 for a code part, then you will have pre-posting available on purchase order lines.

Any value entered as pre-posting for PO line will be moved to arrival transaction. You must consider code part demands and override too.

Hope this helps

I have M102 set up to record the preposting, however the Business Event prevents the preposting from affecting the Financial Transaction, so the M102 becomes pointless for inventory transactions.

Can you send M1 and M102 screen shot together? If your setup is correct, M102 will carry preposting value to M1 when registering arrival.

Hello,
I think it is as designed. 
M1 is a stock account, and expectation is that inbound and outbound transactions related to same part and location will share same M1 postings (considering additionally project-related stock, the only preposting alowed). This way when you receive part and then issue it, you will have accounting balance zero.
Allowing preposting on stock account would lead to different posting of receipt and issue (as usually preposting e.g. on PO line is different than propsting on material requisition), and your stock account would not get closed.
 

Hi,

Adam is 100% correct.   I could show how to make the changes, however you would end up with bigger issues.   M1 inventory (except for the project management project ID) is not retained with the quantity received / linked with that quantity as it is blended with other inventory.  As such when you move that quantity out of inventory there is no function that knows that quantity and what code string was assigned to that quantity.  

Example prepost PO lines 1, as CC100, line 2 as CC200 and line 3 as CC300.   If M1 was allowed to pre-post we would have CC100, CC200, CC300 as part of the debit postings.  It gets even worse if we use the distributed pre-posting.    When that quantity comes out of inventory, we can no way to control / ensure that any given quantity is then also attached to the correct pre-posting when the M1 is reduced by the credit.    

Given the question what business requirement / problem are you trying to solve. We can probably craft a solution to that requirement. 

Best regards, 

Thomas