Automatically Performing External Reconciliations 
You can perform automatic reconciliations when you need to reconcile a large number of transactions, or when you need to reconcile a range of business partners or G/L accounts. The process for automatically reconciling business partner transactions or G/L accounts is similar.
SAP Business One performs automatic reconciliations for pairs of transactions, and the reconciliation is done separately for each business partner or G/L account successively. If you allow automatic reconciliations with differences, SAP Business One posts any differences found to the automatic reconciliation difference account.
Note
If bank statement processing is activated in SAP Business One, you must perform external reconciliations directly within the bank statement processing functionality. Do not use this function to reconcile transactions from your bank statements. For more information, see the online help for SAP Business One and How to Use Bank Statement Processing in Release 2007 in the documentation area of SAP Business One Customer Portal at http://service.sap.com/smb/sbocustomer/documentation.
Prerequisites
To perform automatic reconciliations with reconciliation differences, you have to define an automatic reconciliation difference account. For more information, see Defining an Automatic Reconciliation Difference Account.
Procedure
From the SAP Business One Main Menu, choose
Banking 
Bank Statements and External Reconciliations Reconciliation 
.The External Reconciliation - Selection Criteria window appears.
To specify whether to reconcile transactions of business partners or G/L accounts, from the Select Source dropdown list select Business Partner or G/L Account.
Select the Automatic radio button and specify the selection criteria.
Choose the Reconcile button.
Result
SAP Business One reconciles the transactions according to the parameters you defined and then displays the External Reconciliation window.
The transactions displayed in the upper tables are the ones created for the selected G/L accounts or business partners but could not be reconciled according to the parameters you defined in the selection criteria window.
You can reconcile the relevant transactions manually. For more information, see Manually Performing External Reconciliations.