There are times when you lose your primary mobile number for some reason. The mobile number is tied with many services, such as the bank account, Aadhaar, and WhatsApp among others. It becomes necessary for you to get a new SIM card with the same mobile number. But, what if you are happy to go with a new mobile number? You can change your mobile number at all the places mentioned above but we are going to list how you can change your WhatsApp number.
Changing your WhatsApp number is a thoughtful step as your contacts may not have the new number. Some of you may like this as the daily onrush of messages and forwards will likely lessen. In any case, making the switch to another number on WhatsApp is not really difficult and here’s how to do it:

    Open WhatsApp after you have bought a new SIM card and activated on your phone
    Tap on the three-dot menu available at the top-right corner on your Android phone and go to settings. On iOS, just simply navigate to the Settings tab
    Tap on Account within the Settings menu
    Now, tap on Change number to proceed with changing your number
    WhatsApp will give you a quick list of things changing the number will ensue for your chat experience. Tap Next
    Now, enter your old mobile number in the first text field and the new one in the second field. Your new mobile number should be within your reach to access OTP
    Hit Next, followed by giving confirmation to WhatsApp for receiving OTP on your new number
    WhatsApp will detect OTP on its own (if you have given it necessary phone permissions) if the SIM card is on the same phone. If not, enter the OTP manually
You are now done with the process of changing your WhatsApp number. Your groups and chats remain intact after changing the number but only the people in groups get informed of this move. Individual chats still need at least one message from your new number.