You should really check the contract notes and ledger. I do the same. Zerodha is really honest I feel. But I have noticed that they too charge more money in terms of STT and stamp duty.
What Zerodha does is this: in every contract note, they round off the STT and stamp duty charges. First of all there is no need to round them off. Everything is digital but they still do it.
But when you check the PNL TAX statement you will see that they report the total STT and stamp duty in three or four places of decimal. Now why is this so?
Why report in decimal in TAX statement but in round off way in contract notes?
I feel so what Zerodha is supposedly doing is that they are collecting higher STT and stamp duty from customer by rounding them off. But at the time of depositing the STT and stamp duty to government, they are depositing the lower but correct amount of what they should have charged in the very first place to their customers.
This is a minor issue I guess and I have noticed that all brokers round off the STT and stamp duty but not the other charges like GST, exchange charges etc so I guess all brokers are exploiting some loophole in our laws I guess.
I have only noticed that IBKR doesn’t round off the STT and stamp duty in their contract notes. I am not recommending Ibkr here but just stating the facts. In fact I love Zerodha and use their platforms for 90 percent of my trading.