Real internal order in SAP should be settled to the final receiver periodically. The final receiver could be cost centers, business process, assets, etc. The settlement rule should be maintained first in the internal master record before a setllement can be executed.

After you’ve run final settlement of your Internal Order, you can still reverse the last posted settlement. Just follow this procedure, a very useful guide and reference.

Path: SAP Easy Access Menu → Accounting  → Controlling → Internal Orders → Period-end Closing → Single Functions → Settlement → Individual Processing.

Transaction Code: KO88

Go to Settlement menu, then select Reverse.

If no other errors encountered, your last period settlement is then reversed succeffully.