First open your imo app, then go to ur profile then imo account settings then u can change ur imo number. There is a option of changing imo number. You can change it from ther (the option).
If you want to change your imo account number Here I will show you How to change imo account number.Do you want to change the mobile number for some reason? If you have changed your number to a new one, you don't have to worry about the imo account ...So the question here is can IMO account be used without providing your phone number? The answer is yes. One can use IMO app without the ...