I already have a trading and demat account with Kotak Securities. They charge 0.59% on delivery trades. Since I am a long term investor, I buy smaller lots. 20 rupees a trade is quite high for me. For example, I purchased 1 share of SunPharma today at 486. I will pay about 3 rupees as brokerage to Kotak as compared to the 20 to Zerodha. I may buy 1 share every day of different companies or ETFs. So, I don't think Zerodha is for everybody.
However, they do have a 0.1% delivery plan that I have asked them about. Lets see how viable is that.
Also, do they charge for opening a trading account? Pretty much all brokers do it for free these days. I am a classic customer with HDFC Bank and they are happy to open a trading account for free with demat free for the 1st year and @ 50% charge for the 2nd year.
I just spoke to Zerodha and they can not link any other demat account with the Zerodha trading account other than IFSL. You NEED to have or open a new demat with them. For Example, I can not link my Kotak Demat account which is also NSDL. I'd say deal breaker