You can invite a user only if their Zoho account is under the same domain as your organization.
Let’s say that your organization was created in the India data centre (accounts.zoho.in). However, the account of the user you want to invite is in the US data centre (accounts.zoho.com). Since the data centre of the user is different from that of the organization, you’ll not be able to invite the user.
However, there a couple of workarounds you can use to invite a user from a different domain. Here’s how:
Warning: Deleting your Zoho Account will permanently delete all organizations from various Zoho products linked to your account.
Books
Online accounting software
for small businesses.