SAP F.13 clearing account (SAPF124) is used in the lockbox program.

When the program is first run it posts :

Dr.  Cash in Transit

Cr.  Lockbox clearing account.

This posting is an open item to the lockbox clearing account. 

When a customer's invoice is cleared in the second part of the 
program run, the program posts:Dr.  Lockbox clearing account  

                                              Cr.  Customer. 

Periodically, the Lockbox clearing account should be cleared
to move all the equal debits and credits from an open status
to a cleared status.

Procedures :
1. Go to Tcode F.13

Automatic Clearing without Definition of Clearing Currency (SAPF124)
screen will be displayed.


2. Select select at least one of three optional fields: 
       - Customers
       - Vendors
       - GL Accounts.

3. Select Posting parameters.
    Eg.  Test run

4. Selecy Output control 
    Eg. Detail list with errror log

5. Execute

6. The below screen will be displayed


7. Click "BACK" to go to initial screen.

8. Clear the Test run checkbox.

9. Execute

10. A warning message at the bottom of the screen appears
stating that the “program run is a production run”.

11. Click Enterto continue with the production run posting.

12. The below creen will be displayed