Now that you’ve set up SMS as a channel, learn how to handle any inbound SMS messages from your customers. This can be entirely automated, or you can unlock a whole new channel for your support team, quickly responding to SMS messages through your Inbox with all your conversations in one place.
Inbound SMS can come via:
SMS replies - A customer reply from an outbound SMS message you sent.
Customer initiated SMS contacts - If you’ve shared your SMS number as a support or contact line, a customer can start an SMS conversation with you.
These can be handled in one of two ways:
Keyword Auto-responses - When customers message a specific keyword, they can receive an automated response.
SMS Conversations - If you have 2-way SMS conversations turned on, then for non-keyword messages, a new conversation will be created in the Inbox where teammates can reply.
We’ll go through how to set up both of these options.
Keywords and auto-responses
Many inbound SMS messages can be handled with auto-responses and actions using common keywords such as HELP, INFO, STOP, START etc. To find keyword responses, go to Settings > Channels > SMS and click on Automated keyword responses:
Default keywords and behaviors
Keywords | Action | Default Auto-response | Notes |
UNSUBSCRIBE, QUIT, EXIT, STOP, STOPALL, CANCEL, END | Opt-Out from Marketing SMS | [Workspace Name]: You have been unsubscribed from SMS marketing. No more marketing messages will be received from this number. Reply START to re-subscribe. | This is a compliance required keyword and the response needs to be explicit about the customer being opted out and what they can do to resubscribe. |
START, UNSTOP, SUBSCRIBE, RESTART, RESUBSCRIBE | Opt-in to Marketing SMS | [Workspace Name]: You have successfully been subscribed to marketing messages from this number. Reply STOP to unsubscribe. Msg & Data Rates May Apply. | These keywords automatically opt a customer back into receiving SMS. The auto-response message should confirm this. |
INFO, HELP, DETAILS | None | [Workspace Name]: Reply STOP to unsubscribe. Msg&Data Rates May Apply. | These keywords have no action but should direct the customer to information about where they can get help, how to unsubscribe, and ideally why they are on this list. |
If no keyword is recognised | None | [Workspace Name]: This keyword was not recognized. Reply HELP for help, STOP to unsubscribe. Msg & Data Rates May Apply. | If you don’t have 2-way SMS turned on, this auto-response will be sent. It should explain to the customer that their message was not received/read and direct them where to go instead. |
STOP 🇺🇸 | All US SMS Blocked | You have been unsubscribed from SMS. Msg&Data Rates May Apply. | In the US, STOP is enforced at the network level for both toll-free and local (10DLC) numbers. If a customer responds STOP, any further SMS messages from us to that recipient are blocked. We encourage you to use other opt-out methods in the US such as the Preferences Center but to avoid carrier filtering, the STOP keyword must be included in messages. |
Actions are behaviors that happen alongside the SMS auto-response being sent.
Editing keyword responses
Inbound keyword responses are always turned on. You can edit the default responses to make them fit your brand and tone, as long as they still fit the keywords a customer sends.
To edit a response, hover over a keyword group row and click the edit icon next to the default response:
This will open an SMS response composer where you can click to edit the auto-response text.
Auto-responses are text-only and can’t include any emojis or attributes. We recommend keeping an auto-response under 160 characters to avoid splitting the message into multiple segments and incurring extra charges per message.
Custom keyword responses
You cannot create your own custom keyword responses in your SMS settings however if your Intercom subscription includes Workflows, you can create a channel specific workflow to send a response based on the content of the Users inbound message. You can also set up conditional branches based on the keywords mentioned:
Inbound SMS conversations
When a non-keyword inbound SMS message is received, you can choose to have that message trigger a new Inbox conversation over SMS with your teammates.
With true 2-way SMS, you can make the most of those key moments when you have your customers' full attention - and use them to convert, activate, and retain customers much more effectively.
After a customer sends their first message, you can trigger a workflow to deflect, triage and route inbound SMS conversations more efficiently.
To turn these inbound SMS conversations on or off, go to Settings > Channels > SMS and click on 2-way SMS.
2-way SMS is a global setting which either makes all non-keyword messages go to the inbox if it’s turned on, or none will if it’s turned off.
It’s great to keep this turned on as another communication channel, but you may want to turn it off if you’re unable to monitor the inbox, or don’t want the associated messaging costs that come from SMS conversations in the inbox. Learn how SMS pricing works here.
You’ll need Inbox seats in your workspace to use this feature.
Inbound geo-restrictions
Customers can message your workspace phone number from another country, but due to cost and regulatory implications, auto-responses and SMS replies from your teammates can only be sent if you have an activated phone number in the country the customer messaged from.
For example, if you have a US number activated and you advertise that number on your website as a support channel, a customer in Germany can send an SMS to your number which you can receive but not respond to.
SMS keyword replies
If a customer sends a keyword reply from another country, no keyword auto-response is sent to the customer.
The auto-response is still included in your outbound SMS reporting.
What are tapback reactions in SMS conversations?
Tapback reactions in SMS conversations are the reactions (Loved, Liked, Laughed, and so on) that customers send to your SMS messages from an iPhone or Android phone. Use this section if you're a teammate managing SMS settings and want customer reactions to show on your message instead of arriving as a new reply. Reactions are inbound only: teammates can't send reactions over SMS.
A phone can't send a real reaction over SMS. Instead, it sends a new text that quotes your original message, such as Liked "Your order has shipped". When Show tapbacks as reactions is on, Intercom recognizes these texts and adds the reaction to the message it quotes. When it's off, these texts arrive as customer messages.
How to show tapbacks as reactions in the Inbox
Go to Settings > Channels > SMS.
In the SMS Response Handling section, open Tapback reactions (marked Beta).
Turn on Show tapbacks as reactions. Changes save immediately.
The Show tapbacks as reactions setting is on by default for workspaces that set up SMS on or after October 28th, 2026. Workspaces that set up SMS before that date need to turn it on.
What happens when Show tapbacks as reactions is on?
The customer's reaction shows as an emoji on the message they reacted to, in the conversation in the Inbox. No new customer message is added.
Reactions to SMS sent by teammates from the Inbox, by Fin, by workflows, and through the REST API are all matched, as are reactions to the outbound SMS message that started the conversation.
The reaction doesn't reopen or unsnooze the conversation, no workflow runs, Fin doesn't reply, and it doesn't count as a customer reply.
If the customer removes their reaction on their phone, the reaction is removed in Intercom too.
iPhone's classic tapbacks map to ❤️ 👍 👎 😂 ‼️ ❓. Reactions with any emoji (iOS 18 and later, and Google Messages on Android) keep the emoji the customer picked.
Tapbacks shown as reactions don't create a customer message, so they no longer appear in reply-based or message-based reports.
What happens to a reaction on an outbound SMS that nobody replied to?
A reaction to an outbound SMS that the customer never replied to doesn't open a conversation in the Inbox. The reaction shows on that message's card in the contact's profile, under All conversations.
What are the limitations of tapback reactions in SMS?
Supported phones and languages: Reactions are recognized from iPhone Messages and Google Messages on Android, in English, Spanish, and Portuguese. Reactions from other apps or in other languages arrive as normal customer messages.
Quoted message must match: Intercom matches the quoted text against the most recent SMS messages it sent to that customer. If the quoted message is much older, the text differs, or the message is in an earlier conversation, the reaction arrives as a normal customer message.
Images and attachments: Reactions to images and attachments arrive as normal customer messages.
Workflows that act on tapback text stop running: For example, a workflow that closes the conversation when a customer replies "Liked…" doesn't run for tapbacks while Show tapbacks as reactions is on, because no message arrives. Review workflows like this before you turn the setting on.
REST API and webhooks: A tapback shown as a reaction isn't a conversation part, so integrations that read customer replies don't see it.
Not retroactive: Turning the setting on doesn't convert tapbacks that already arrived as messages.
Customers see no change: Their phone shows the reaction as usual, and Intercom doesn't send anything back.
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