You can recall and make changes to any expense report that you have submitted, even if the report has been approved, provided that the claim has not yet been reimbursed.
To recall an expense report:
Click My Expense Reports in the navigation bar.
Click Submitted in the status filters at the top left.
Click the expense report to view it.
Click Call back.
You receive a recall confirmation email.
The report status is set back to Pending completion and can be accessed from the corresponding status filter button.
When you have modified your report, you can resubmit it. You do this in the same way as for submitting a new report - see Submitting an Expense Report. You need to resubmit a recalled expense report even if it has been previously approved.