Question: how to check airtel data balance on iphone?
Answer: Open the phone app on your mobile device. . ... 
Dial *121# and press the call button. Use the dial pad to dial the USSD code and press the green button to send the call. ... 
Enter 5 and tap Send. 5 is the menu option to check your balance. ... 
Enter 1 and tap Send. This displays your data balance.