Many traders trade in options and when the option premium value becomes too less they let it expire . If you have been doing this stop letting your options expire because now you will have to pay more.
You have to pay brokerage on expired options
Before brokerage can be charged on the trades executed on exchanges only. But now brokers can charge brokerage on Expiry / Exercise / Assignment of contracts on EXPIRY. Check the below circular of National stock exchange.
You have to pay more STT
When you buy/sell options stock transaction tax(STT) is levied on the option premium at the rate of 0.017%. But when you let it expire the STT is applied on strike price at the rate of 0.125%. Lets understand it with an example
Any client buys an 500 Nifty
Spot price: 5010
Strike price: 5000
Premium earned :10
Quantity: 500
If any client has an buy
Case 1: STT when Client square off position in the open market
STT = quantity x premium x 0.017% = 500 x 10 x 0.017% = 1
Case 2: STT when Position kept open and exercise By Exchange
STT = spot price x quantity x premium x 0.125% = 5010 x 500 x 0.125% = 3131
So you can see the huge difference in the STT. Again this will
Therefore its always good to square off the options than letting it expire.