Why does the maximum number of characters allowed in an SMS decrease when entering certain characters?
The SPL is able to send SMS’s with characters other than the basic English alphabet. Certain characters use more space than others – this can mean that a basic SMS may only be able to carry 70 characters rather than the standard 160 characters. If you prefer to keep the message size to a maximum you can go to Messaging > Menu > Options >Account Options > Text Messages account and uncheck the “Use Unicode when necessary” checkbox.