What Are the Restrictions and Limitations on SMS Messaging?¶

You can send at most 60 SMS messages to a single phone number within one hour and 200 within 12 hours.

This limit is applicable only to SMS messaging. There is no limit on the number of messages you can publish to a topic.

If an SMS message contains more than 1,000 characters, the SMS message cannot be sent to the SMS endpoint.

The following table describes the rules for calculating the number of characters in an SMS message.

Character Counting Rule	Remarks
SMSs in English: GSM-7 characters are used for counting. If an SMS contains 160 characters or less, it is counted as one SMS. If an SMS contains more than 160 characters, every 153 characters are counted as one SMS.	If an SMS contains 158 English characters, it is counted as one SMS. If an SMS contains 164 (153 + 11) characters, it is counted as two SMSs. If an SMS contains 320 (153 + 153 + 14) characters, it is counted as three SMSs. For example, if an SMS template contains variable ${NUM_8} set to 123456, that variable is counted as six characters.
SMSs in other languages: Each Unicode character, such as a letter, digit, punctuation (full-width and half-width), and space, is counted as one character. If an SMS contains 70 characters or less, it is counted as one SMS. If an SMS contains more than 70 characters, every 67 characters are counted as one SMS.

Character Counting Rule

Remarks

SMSs in English:

GSM-7 characters are used for counting.
If an SMS contains 160 characters or less, it is counted as one SMS.
If an SMS contains more than 160 characters, every 153 characters are counted as one SMS.

If an SMS contains 158 English characters, it is counted as one SMS. If an SMS contains 164 (153 + 11) characters, it is counted as two SMSs. If an SMS contains 320 (153 + 153 + 14) characters, it is counted as three SMSs.
For example, if an SMS template contains variable ${NUM_8} set to 123456, that variable is counted as six characters.

SMSs in other languages:

Each Unicode character, such as a letter, digit, punctuation (full-width and half-width), and space, is counted as one character.
If an SMS contains 70 characters or less, it is counted as one SMS.
If an SMS contains more than 70 characters, every 67 characters are counted as one SMS.

last updated: 2025-02-21 11:17 UTC - commit: 6f07b304816549ae540f28f6193a0d8bf2074c20