All Products
Search

This Product

    Chat App Message Service:SMS fallback

    Document Center

    Chat App Message Service:SMS fallback

    Last Updated:Oct 20, 2025

    SMS fallback refers to the mechanism where, if a message fails to reach its target under specified conditions within a designated time, an SMS is used to send the message instead. Using SMS fallback can improve message delivery rates and ensure the timeliness of the messages. This method is typically used for high-timeliness messages that require a high delivery rate, such as One-Time Passwords (OTPs) or deadline notifications.

    Prerequisites

    Procedure

    Enable SMS fallback

    1. Log on to the Chat App Message Service console.

    2. Create a fallback rule.

      image

    3. Create a fallback policy.

      image.png

    4. Click Channel Management in the left navigation pane, and select the channel that requires SMS fallback.

    Note

    Only WhatsApp and Viber channels support SMS fallback.

    1. On the channel details page, click Service Settings in the left-side navigation pane.

    2. Turn on the Activate SMS switch.

      image

    Note

    The SMS fallback feature can only be used when the Activate SMS switch is turned on.

    Use the fallback feature when sending a message

    1. Click Channel Management in the left-side navigation pane of the console, and select the channel.

    2. Click Message Sending in the left-side navigation pane of the channel details page.

    3. Set Language, Send Message, Send Account, and Send Type as needed.

    4. Select the fallback policy from the Fallback Policy dropdown list.

    5. Set Fallback Time.

      • Undelivered: The message has not been delivered to the recipient.

      • Not Read: The message has been delivered to the recipient, but has not been read.

      • Send failed: The message sending failed.

    6. Set Fallback Message Content, which specifies the content to be sent if fallback is triggered.

    7. Set Fallback Duration. Unit: seconds. If the message has not reached its target and the corresponding return status has not been obtained within the set fallback duration after sending, fallback will be triggered. The minimum value is 60, and the maximum value is 43200. If the fallback duration is not specified, fallback will only be triggered upon receiving the corresponding delivery report. For example, if the fallback time is set to "Unread" and the fallback duration is left unspecified, SMS fallback will be triggered once an unread message status is confirmed.

    Important

    If a delivery report is received after SMS fallback has been triggered, the message will be charged twice. For example, if you send a WhatsApp message and use the message fallback feature with the fallback time set to "Undelivered" and the fallback duration set to 60 seconds, the following scenario may occur:

    After 60 seconds, if no delivery report for the WhatsApp message has been received, the SMS fallback will be triggered, and the fallback content will be sent. If the delivery report for the WhatsApp message is then received at 80 seconds, both the SMS message fee and the WhatsApp message fee will be charged.

    image.png

    1. Set Import Method, which specifies how recipient phone numbers are imported.

    2. Click Send button to send the message.