We can provide the following solutions as workarounds.
For directly posting to a G/L account, you can use the blanket purchase order. Postings to various account assignment categories can also take place here.
To do this, you must create a dummy vendor via Transaction XK01 (Create Vendor).In order that postings cannot be made to this creditor, you can create a reconciliation account for this creditor which is blocked for postings.
Then, create a blanket purchase order using Transaction ME21 with purchase order category NB (Standard purchase order), item category B (Limit) and account assignment category U (Unknown).
Follow the procedure below when making entries via Transaction MR1M:
1. Entry with reference to a purchase order and a delivery note:
Enter the invoice/delivery note as usual.The G/L account posting is now entered via the blanket purchase order.
To do this go into assignment and enter the blanket purchase order also for the existing assignment.
Go back to the item overview screen.
Via 'Account assignment' you arrive at the account assignment screen and you can enter your G/L account postings there.
2. Posting to G/L account only:
Here, the invoice is processed with direct reference to the limit account assignment. Note that the invoicing party must be maintained on the header screen of the transaction. In the item screen of the invoice, you can now go directly via "Account assignment" to the account assignment screen and enter the G/L account postings.
Note: this solution as a workaround only solves the problem if all items have the same debit/credit indicator. If different debit/credit indicators exist in an invoice, there will be no solution as workaround.