After deleting the account, the user can open a new account using the old email address. 

 To delete or close a free Desk account

1. Click the Hamburger Menu in the top-left corner of the screen.
   
2. Click Settings   at the bottom of the screen.
   
3. Go to Privacy and Security.
   
4. Click Close Account. On the Close Account page, click Proceed.  You will be redirected to accounts.zoho.com to verify your identity.
   
5. Enter your Password and click Confirm Password. You will be redirected to a page listing the apps associated with your Zoho Desk account.
   
6. Click Next. A page listing the app-specific organizations will be shown
   
7. Click Next. You will be redirected to the Close Account page again.
8. Select a Reason for closing the account from the drop-down and a Feedback.
   
9. Click Close Account.
   

To delete a paid account from the mobile, the user should cancel their subscription or downgrade it to a free account and then delete.