This is one of the most commonly asked questions by a traveller who wishes to travel to India. Smartphones and Internet are the essence of life now, however much you want to deny that! However, the answer to this question is not polar. Let’s first look at what all is there that can go wrong. Why will my phone not work in India?Your phone may not work in India with any of the local sim cards unless it is unlocked. In most of the parts of the world, mobile phones are locked to their telecom carriers and only they (your telecom carrier) can unlock the phones for you. You will not be able to insert another sim or use it with another carrier unless you pass their criteria of getting the phone unlocked and then go through the procedure which can take time and may cost you money of you get it done privately.Therefore, if you are getting an iPhone 6s, iPhone 6 Plus or 6s Plus from USA with you, make sure it is unlocked beforehand. Your phone may also not work, even if unlocked unless the GSM bandwidth of your phone is compatible. In India, the compatible GSM bands are as follows:2G capabilities: GSM 900, GSM 18003G capabilities: UMTS 900, UMTS 21004G capabilities: LTE 850 (5), LTE 1800 (3), LTE 2100 (1), LTE 2300 (40), LTE 2500 (41) Some key points to explain the necessity of this: Lower frequency network bands provide higher coverage. Higher frequency network bands provide higher data speeds. Proper Bands are required for VoLTE (Voice over Long-Term Evolution) services as it is a standard for high-speed wireless communication for mobile phones and data terminals. Therefore, one needs to identify their home GSM bands and compare it with India’s for a functional phone.