Two-way SMS basics - how replies work
What is two-way SMS?
Two-way SMS means customers can reply to your messages and you can respond back.
This is useful for:
- appointment confirmations
- questions and follow-ups
- simple back-and-forth conversations
- managing opt-outs and replies in one place
When replies are supported
Whether customers can reply depends on the sender option you use.
Replies are supported when sending from:
- a Mobile Message dedicated number (recommended for two-way messaging)
Replies are not visible in Mobile Message when sending from:
- your own mobile numberreplies are sent back to your phone directly
- replies will not appear in the Messenger
Replies are not supported at all when sending from:
- a custom sender ID (business name)
Custom sender IDs are designed for one-way messaging only.
Where replies go
Inbound replies are delivered based on the sender option used.
- Dedicated numberreplies appear in the Messenger
- replies can also be sent to email or a webhook, depending on your settings
Your own mobile number
- replies are delivered to your phone
- replies do not appear in Mobile Message
Custom sender ID
- replies are not supported
Replying back to customers
When using a dedicated number, you can:
- view the conversation in the Messenger
- send replies directly from the platform
Sending a reply is an outgoing SMS and uses credits like any other message.
Important reply behaviour
- Replies are always linked to the number the original message was sent from
- Changing sender options changes where replies are delivered
- Certain keywords (such as STOP) are handled as opt-outs and should not be replied to
Testing two-way SMS
To test two-way messaging within Mobile Message:
- Send a message to your own mobile from a Mobile Message dedicated number.
- Reply to the message from your phone.
- Confirm the reply appears in the Messenger.
- Send a response back from the platform.
If a reply does not appear in the Messenger, the most common reasons are:
- the message was sent from your own mobile number
- the message was sent using a custom sender ID
- replies are configured to be delivered elsewhere (for example, email or a webhook)