Simple steps to change/edit Email and Mobile Number of Authorized Signatory in GST Portal (For proprietorship):
Login to GST portal i.e. https://services.gst.gov.in/services/login with your existing user id and password.
Click on the registration Tab and select the Application for Amendment of Non-Core fields in Registration Particulars (For all types of registered persons).
Click on the Promoter/ Partners tab and click Edit
Change email and mobile number or any one as per requirement and save.
Verify the Mobile No. and email address (verification done through OTP ).
After verification through OTP, submit the application.
Confirmation Mail and message will come after necessary changes.
Necessary changes done successfully.
Please mail us, if you are still facing any issue.