Why is it not recommended to copy text from programmes (e.g. Microsoft Office and Emails) and paste on message box when composing message in the web portal?

This is a SMS technology limitation across the board which may result in some special characters turning from ASCII Text into Unicode characters and affect the eventual SMS count and billing to the customer. Hence, to overcome this limitation, the user will either type into the message box manually or copy and paste to “notepad” and then replicate that actions to the message box from “notepad”.