I have been using my ICICI Bank credit card for 18 months with a clean repayment history. How can I request a credit limit increase, and what factors does the bank consider?

I closed my HDFC card last year. The process took exactly 7 days. They sent a confirmation email and a closure letter by speed post. Tip: pay off the full outstanding and request closure only AFTER the payment reflects. Calling repeatedly with a zero balance is the fastest path.