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SMS messaging

Updated

Voice lets your organization send and receive SMS and MMS messages from a business phone number. Conversations are organized in an inbox by contact thread. You can reply to inbound messages, send outbound messages, save templates for common replies, and send broadcast messages to a list of recipients.

US organizations sending to long-code numbers are required by carriers to register a 10DLC brand and campaign before sending at volume.

Viewing the SMS Inbox

  1. Go to SMS Inbox in the Voice navigation.
  2. The inbox shows all active conversation threads, sorted by most recent activity. Each thread is tied to a contact number and the business number it came in on.
  3. Click a thread to open it and see the full message history.
  4. New inbound messages that you haven't read appear highlighted. Click Mark Read to clear the indicator.

Sending a New SMS

  1. In SMS Inbox, click Compose.
  2. Enter the recipient's phone number or select a contact from the directory.
  3. Select the business number (sender) to send from, if your organization has multiple SMS-capable numbers.
  4. Type your message.
  5. Click Send. The message appears in the conversation thread.

You can attach images or files to send an MMS by using the attachment option in the compose window.

Replying to an Inbound Message

  1. Open the conversation thread from the SMS Inbox.
  2. Type your reply in the message field at the bottom.
  3. Click Send. Replies go out from the same business number the original message came in on.

Using SMS Templates

Templates save time for common replies. To use a template:

  1. While composing a message, click the Templates icon.
  2. Select the template you want to use. The text is inserted into the message field.
  3. Edit as needed and send.

To manage templates, go to SMS Templates in the admin panel. Create, edit, or delete templates from there.

Sending a Broadcast

A broadcast sends one message to many recipients at once:

  1. Go to Broadcasts and click Create Campaign.
  2. Give the campaign a name.
  3. Upload a recipient list or enter numbers manually.
  4. Write the message content.
  5. Schedule the send time or send immediately.
  6. Broadcasts are dispatched at a rate-limited pace to comply with carrier rules.

Opt-Outs and STOP/HELP

Opt-out handling is automatic. When a recipient replies STOP, they are added to the opt-out list and future messages to them are blocked. Replying HELP sends an automatic help response. These behaviors are required by US carriers and cannot be disabled.

To view the opt-out list or manage blocked numbers, go to Spam in the admin panel.

10DLC Registration (US Long-Code SMS)

US carriers require that businesses using 10-digit local numbers (long-code) for commercial SMS register their brand and use case. Without registration, messages are likely to be filtered or blocked.

To register:

  1. Go to 10DLC in the admin panel.
  2. Register your brand — your company's legal name, address, and EIN.
  3. Create a campaign for each messaging use case (e.g., customer care, appointment reminders, marketing).
  4. Submit. Registration status updates within 1–5 business days.

Once approved, messages sent through registered campaigns are less likely to be filtered by carriers.

FAQ

Can I send SMS from any phone number in my organization? Only numbers that are SMS-capable and configured as SMS inbox numbers can send and receive SMS. Go to SMS Inbox to see which numbers are active.

What is the sending rate limit? Outbound SMS is rate-limited to 100 messages per minute per organization. Broadcasts are dispatched within this limit automatically.

Can I send MMS (pictures and files)? Yes. Use the attachment icon in the compose window to attach an image or file. MMS support depends on the recipient's carrier.

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