Exchange your airtel mobile SIM for a free 4G SIM

http://www.airtel.in/4g/sim-swap.html


Steps:-
SMS SIM <20 digit SIM number> from your existing airtel connection to 121
The 20 digit SIM number is available at the back of your new SIM card
Reply with 1 to confirm your request
Wait for the phone to get disconnected from the network. Then change the SIM and switch it on to get connected again.
Your new 4G airtel SIM will be active within 5 minutes
No need to change your mobile number
You can also upgrade to an airtel 4G SIM at the nearest airtel store