SMS messages have a character limit of 160 characters. If that limit is exceeded, your message is split up into multiple parts in order to deliver it to the recipient's phone. This is called message concatenation. Usually, the final message is delivered as one long message on the user's phone, despite having been split up for the sending process. In some cases, however, it can happen that the message is delivered in multiple parts. There are different reasons why this might happen:

1. Some countries do not allow messages longer than 160 characters to be delivered to the end-users' phone in one piece. All concatenated messages will only deliver split up into parts of 160 characters. Please make sure to check our Country Restrictions page to check if this is the case in your destination country. 
2. If 1. does not apply, then there might be an issue with the connection that is causing the messages to be delivered in multiple parts. If this is the case, please reach out to our Support Team to report this issue. To help the investigation, please provide some samples in your email. Ideally, you want to share between 3-5 samples with us. These should include the recipient's phone number and a timestamp. If you can provide a screenshot from a user's phone that shows the split messages, even better.

If only one or two of your users are experiencing this issue, and the country you are sending to supports longer messages, please make sure to ask these users to restart their phones and send them another test before reaching out to Support. This helps to rule out any problems with the recipient's phone itself.