Most messages containing standard letters and numbers (what's on a keyboard) will be allowed up to 160 characters
Any message that contains ASCII characters will be allowed up to 140 characters, reference: http://www.asciitable.com/mobile/
Any characters outside of the ASCII character set (emojis, non-English characters) will have a maximum of 70 characters per message
For most vendors throughout the world when you send a large text message (plain text over 160 characters), the large message will show up as one large message, even though the message is divided into multiple segments.
Some CDMA carriers may split the message into segments on the users handset (Sprint in the USA for example).
Our API will return to you the segment count of the message you delivered so you can appropriately bill on your end.