How long can a text message be?
Text messages or SMS (Short Message Service) is designed to send short messages between mobiles. In most instances, these are limited to 160 (or 140 characters in the USA). However, most mobiles will take longer messages and split them into segments.
If your phone splits a message into multiple segments you may get charged for each segment, depending on your phone, the network receiving the message and the recipients type of phone.
You can see how many segments each of your SMS have in your usage, and each will have a separate charge. The time between segments is usually 2-3 seconds.
Emojis & special characters matter
Characters outside of the standard A-Z character set (like e.g. emojis, accented letters, Chinese, Japanese, Korean, Arabic characters) are automatically encoded by your phone. These special character uses more bytes per character, limiting you to 70 characters per segment.
iPhone and Smart Punctuation
Are you using an iPhone? Text segmentation has become an issue world-wide with some of the latest iOS 11 updates. Please ensure that you have turned off Smart Punctuation; in the keyboard settings. If this is on and you use an apostrophe, dashes or quotes then the phone splits the message into 70 character chunks rather than 160. Smart Punctuation can also cause data inputting issues on various websites and web forms.