Answer
The lack of agreement between the balance in Bank account as per company books and the balance as per bank statement, has two causes:
1. Time lag
2. Errors
Work Step by Step
1. That prevent one of the parties to record the transaction in the same period. The example, it may take several days between the time a company pays by check and the date the bank pays that check.
2. By either party in recording transaction. For example, the bank has passed a check of 630 dollars and entered as 360 dollars.