Your cheque book will get invalid if you have an account in these SBI branches

The account holders of all the associate banks that got merged with State Bank of India have to get new cheque books bearing the new IFSC code by December 31, 2017, reports ET.
 
The account holders of banks such as Bharatiya Mahila Bank, State Bank of Patiala, State Bank of Mysore, State Bank of Bikaner and Jaipur, State Bank of Raipur, State Bank of Travancore, and State Bank of Hyderabad will now have to get their cheque books replaced, said the ET report.
 
How to get new cheque books
In order to receive new cheque books, one can visit the nearest bank branch or can even use the ATM or SBI's mobile app to get a new cheque book.
 
SBI officials reportedly said that all the transactions based on old codes will still continue. Even though the new codes have been merged internally, the transactions with old codes would not be held up.  
 
SBI recently changed the branch names, branch codes and IFSC codes of some major branches of Mumbai, New Delhi, Bengaluru, Chennai, Hyderabad, Kolkata, Patna, Ahmedabad, Bhopal, Amravati, Chandigarh, Jaipur, Thiruvananthapuram and Lucknow.

The validity of cheques of former Associate Banks has been extended till 31st December, 2017. Apply now for a new SBI cheque book. pic.twitter.com/wkeuM2M9oI

— State Bank of India (@TheOfficialSBI) October 11, 2017

 
What is IFSC?
Indian Financial System Code or IFSC is a unique 11 digit alpha-numeric code that is used to identify each bank branches participating in any RBI regulated funds transfer system.