Introduction:
Bank Reconciliation Statement (BRS) is a statement that compares the bank balance as per the cash book with the bank balance as per the pass book. It helps in identifying the reasons for the differences between the two balances and ensures the accuracy of the financial records.

Format of Bank Reconciliation Statement:
The format of the Bank Reconciliation Statement is as follows:

Bank Reconciliation Statement
Date: __________

Particulars Amount (₹)
Balance as per cash book _________
Add: Deposits in transit _________
Less: Outstanding checks _________
Adjusted cash book balance _________

Balance as per pass book _________
Add: Interest credited by bank _________
Less: Bank charges and fees _________
Adjusted pass book balance _________

Treatment of Undercast and Overcast:
Undercast and overcast errors occur when there is a discrepancy in the recording of transactions in the cash book and pass book. These errors can be rectified by following the below steps:

Method 1:
1. Identify the undercast or overcast error by comparing the cash book balance with the pass book balance.
2. Adjust the cash book balance by adding or deducting the amount of the error.
3. Update the adjusted cash book balance in the BRS.
4. Reconcile the cash book balance with the pass book balance by making necessary adjustments for other items such as deposits in transit, outstanding checks, interest credited by the bank, bank charges, and fees.

Method 2:
1. Identify the undercast or overcast error by comparing the cash book balance with the pass book balance.
2. Prepare a separate statement to rectify the error, mentioning the undercast or overcast amount.
3. Update the cash book and pass book balances by adding or deducting the undercast or overcast amount.
4. Reconcile the cash book balance with the pass book balance by making necessary adjustments for other items as mentioned in method 1.

Conclusion:
Bank Reconciliation Statement is a crucial tool for ensuring the accuracy of financial records. It helps in identifying and rectifying errors such as undercast and overcast. By following the above methods, these errors can be treated effectively, thereby ensuring the reconciliation of the cash book balance with the pass book balance.