An SMS message is short by nature. Each SMS message is limited in size to 1120 bits. Each character included in a message requires a set number of bits to encode its data for transmission. The number of bits required for each character is determined by the type of encoding used for transmission.

Possibilities and Limitations with SMS​

SMS messages are text-only. The following special format limitations apply.

Supported

  • SMS messages with the character encoding UTF-8 can contain special characters.

  • SMS messages can contain links to your website. You can shorten the URL by clicking Shorten Links in step 2. Content of the message creation wizard. Note that Mapp Engage cannot track whether your recipients click these links.

  • SMS messages can contain personalizations (both placeholders and complex personalizations).

  • SMS messages can contain Mapp Engage Variables and coupons.

  • SMS sendouts can be limited by a selection. Apply a selection to an SMS message during sendout for more targeted messaging.

Not Supported

  • SMS messages do not contain a subject line.

  • SMS messages do not support images.

  • SMS messages do not support attachments.

  • SMS messages have a maximum length that depends on the type of character encoding.

    • SMS messages sent with 7-bit encoding (ISO 8859-1 or ISO 8859-15) or are limited to 160 characters per message.

    • SMS messages sent with 16-bit encoding (UTF-8) are limited to 70 characters per message. 16-bit encoding allows special characters.

Message Encoding​

SMS messages use either 7-bit or 16-bit encoding.

SMS messages sent with 7-bit encoding (ISO 8859-1 or ISO 8859-15) or are limited to 160 characters per message.

SMS messages sent with 16-bit encoding (UTF-8) are limited to 70 characters per message. 16-bit encoding allows special characters.

SMS messages use 7-bit encoding by default. For a complete list of characters supported by this alphabet, see http://en.wikipedia.org/wiki/GSM_03.38.

If you use characters that the GSM 7-bit alphabet does not support, then the encoding switches automatically to 16-bit. Mapp Engage automatically reduces the maximum message length to 70 characters.

Message Concatenation​

Concatenated SMS is used to overcome the character limitation for single SMS messages. Using this method, Mapp Engage splits messages exceeding the single message limitation into as many as three smaller messages. The message parts are reassembled by the receiving device. Instead of three separate messages, the recipient sees a single text message.

Not every mobile carrier supports concatenated messages.

Each of the messages sent by Mapp Engage includes a header that contains instructions for message reassembly. Because the headers used to reassemble the message increase the size of each message part, the actual maximum size of the SMS is lower.

The message limitation for concatenated SMS messages is shown in the following table:

Bit Size

Encoding

Single message maximum

Total maximum limit

GSM 7-bit

ISO 8859-1 or ISO 8859-15

153 characters

459 characters

16-bit

UTF-8

70 characters

201 characters

If your SMS Message contains a link, you can gain more space by pressing the ​Shorten Links​ button. For more information, see Add Links to SMS​.

Character Count in Mapp Engage​

Below the message input field, the system indicates the current number of characters used in the SMS. You also see how many SMS messages are needed to send the entire message.

The system also recognizes the character format currently in use.

Placeholders and text created through personalisation and Mapp Engage Variables cannot be checked for length by the system. The placeholders are replaced with content during sendout.

If the SMS character limit is exceeded because of personalisation, additional SMS messages are sent.

Related Topics​

SMS Messaging​
SMS Code Types​
Create SMS Message​
Add Links to SMS​