Use
You can change a parked document and complete it step by step. A large number of header and item fields can be changed during this process, including the amounts.
You can make changes to:
However, you cannot change the currency and company code.

The internal system change rules governing document entry are not used in document parking.
Procedure
If you know the document number, enter the company code, document number, and fiscal year.
If you do not know the document number, choose Document
® List. On the selection screen that follows, enter the appropriate selection criteria and choose Execute. The system generates a list with the required documents. Select the required document and then choose Edit ® Select.If you want to change an item, first select this item. The fields you can change are highlighted on the screen.
You can add new line items.
You can mark line items for deletion by setting the amounts to zero.
You can change the line layout variants in the document overview by choosing Settings ® Line layout.

The old document number cannot be reused when changes are made to the document header, for example, to the posting date or fiscal year (by changing the posting date).
If you use internal document number assignment, when a new fiscal year results from changes made to the document header, the document number is changed automatically.
If document numbers are assigned externally, you will have to assign a new number yourself.