Reconcile amounts paid to external vendor for Travel bookings

Question

All,
We are implementing travel expenses in SAP. Employees can use an external provider for booking flight reservations. This external vendor invoices the company for  these expenses on a weekly basis. After the trip is undertaken, the employee enters the expenses. How do we reconcile the money that has been paid to the travel agency and the trips expeenses.
scenario
Step 1 - Employee calls up travel agency and books flight ticket to, say, California. The cost of ticket is 1000 Dollars.
Step 2 - Employee undertakes the trip.
Step 3 - Employee enter the trip expenses. They enter the flight costs that have already been paid by the company as expense type "flght paid" and the difference amounts are paid to the employee.
"Flight paid"    - 1000
Hotel              - 500
The employee is paid 500 dollars through FI.
Now the task of travel administrators is to check whether the amounts invoiced by the travel agencey match the amounts entered by the employees. They also want to ensure that employees mistakenly or intentionall do not enter the receipt type as "Flight" insead of "Flight Paid" when they are filling the travel expenses. What is the best way to handle this reconcilation issyes in travel management.
Appreciate any inputs on this issue.
regards
Sam

Answer 1

Hello Sam,
There are 2 options I could see here:
1) In the release you can customise in table V_T706S_RECEIPT on which the User cannot use the Expense Type "Flight" per.
2) You can use the User Exit EXIT_SAPMP56T_003. In this case it check the data before the user save the trip.
Regards,
Raynard