IRCTC app or IRCTC website helps you book your online Indian Railways tickets through your log in ID and password. To have an IRCTC log in, one needs to register with the IRCTC and in this process, mobile number and email ID are required. Interestingly, one mobile number can be registered with one IRCTC account only. So, in case you changed your mobile number, you will have to either create a new IRCTC account with a new mobile number or change the registered mobile number in your existing IRCTC account. But, the later option is known to very few people. But, it’s possible to change registered mobile number on the IRCTC website or IRCTC App.
Having a mobile number registered with IRCTC account is important because all information related to your Indian Railways train ticket booking to schedule of the train, boarding and departure or in the case of train cancellation, which is common these days, you get informed through the same registered mobile number by the IRCTC.