Hi vivek garg,
from a functional perspective the manual change of several header fields in the invoice are not desirable.
Such a field as incoterms (VBRK-INCO1) is copied from the referenced document, in delivery related billing from the delivery (LIKP-INCO1). Into the delivery it is also copied, from the sales order (VBKD-INCO1), and into there it is determined from the customer master (KNVV-INCO1).
Due to this dependencies in the standard SAP behavior the field is not editable in transaction VF02. A manual change would lead immediately to an inconsistency, because then the incoterms in the sales order and delivery would no longer be the same to the one used in the invoice.
Of course the filling of the field can be influenced by the user-exit mentioned by G Lakshmipathi. Then you would have to program coding to define how the field should be filled differently.
But if I understand your requirement correctly, then you really would like to modfiy manually the field, in VF02, right?
If this is the case, then of course the user-exit, which is executed in the creation phase of the invoice process in VF01, is not useful.
Instead you would have to modifiy the screen 6001 of program SAPMV60A and change the editability of the screen field VBRK-INCO1:
![VF02.gif]()
But since this is hard-coded and no user-exits exists (as explained, some fields are not allowed to be changed!), you would have to modify standard coding of include MV60AF0F_FELDAUSWAHL_SONDERREG for screen-name = VBRK-INCO1 and force a change in screen-input from '0' to '1'.
Let me emphasize clearly that this is not recommended! From an audit perspective you can not deliver the goods with different incoterms than those that are then changed in the invoice. This is inconsistent and for good reason the screen input is deactivated.
Best regards,
Tobias