SBI asks customers to stop using cheque books of these 6 banks SBI asks customers to stop using cheque books of these 6 banks The Customers Of These Six Banks Will Have To Apply For The New Cheque Books From Their Respective Banks. Apart From The Cheque Books, The Old Indian Financial System (IFS) Codes Will Also Become Invalid. News Nation Bureau | Edited By : Vivek Arya | Updated on: 02 Oct 2017, 04:38:43 PM New Delhi: The State Bank of India has asked the customers of its 5 subsidiary banks and 1 other bank to stop using their cheque books as they will be invalid from Sunday. The banks have merged with the largest bank of the country from October 1.