In order to change your phone number in the Upstox account, you will have to open an online service request. To change phone number in Upstox, follow the below mentioned steps: a) Go to www.upstox.com b) Click on 'Sign in' > 'Dashboard' c) Login to the dashboard (Upstox back office) d) Choose and click on the 'Service Request' box e) Then, click on 'Change your Mobile Number" f) Enter the new phone number and verify the OTP. Once after the request is submitted, it will be processed in 24 to 72 hours.