article Support for Group Messaging on 10DLC in MMS

article Support for Group Messaging on 10DLC in MMS https://community.sinch.com/t5/MMS/Support-for-Group-Messaging-on-10DLC/ta-p/9279 <H2 id="MMSGroupMessagingonMM7API-Overview:">Overview:</H2> <P>MMS group chat messaging refers to the capability of sending text messages, multimedia content (such as pictures, videos, audio clips), and other data to multiple recipients simultaneously within a single message thread.</P> <P> </P> <P>Unlike SMS, which typically only supports plain text messages limited to 160 characters, MMS allows for the transmission of richer multimedia content and longer messages. Group chat messaging extends this capability to multiple recipients, enabling users to create group conversations where everyone can participate and view the messages sent by others in the group.</P> <P> </P> <P>Group chat messaging is commonly supported by modern smartphones and messaging apps, allowing users to engage in group conversations with friends, family, or colleagues, and share various types of multimedia content in a single thread.</P> <P> </P> <H2 id="MMSGroupMessagingonMM7API-AvailabilityandReach:">Availability and Reach:</H2> <P>Group chat messaging is available on the 10DLC product for US Wireless carriers: AT&T, T-Mobile US, Verizon Wireless, U.S. Cellular, and Google Voice.</P> <UL> <LI>Currently supported on the Sinch<SPAN> </SPAN><A class="external-link" href="https://developers.sinch.com/docs/mms/7-service/introduction/" target="_blank" rel="nofollow noopener">MM7 API</A> and <A href="https://developers.sinch.com/docs/mms/api-reference/introduction" target="_self">JSON API</A>. </LI> <LI>Up to 20 message recipients supported.</LI> </UL> <P>Please review our <A href="https://developers.sinch.com/docs/mms/7-service/introduction/" target="_self">MM7 API</A> developer documentation for detailed instructions on sending and receiving group chat messages, as well as information on the error codes introduced for group chat. Group chat messaging is also supported on the Sinch JSON API using the <CODE>to-displayonly</CODE> attribute. See the <SPAN draggable="true"><A href="https://developers.sinch.com/docs/mms/api-reference/introduction#group-messaging-with-to-displayonly" rel="noopener noreferrer" target="_blank">MMS JSON API documentation</A></SPAN> for request structure and the <SPAN draggable="true"><A href="https://developers.sinch.com/docs/mms/api-reference/mms-mo-postbacks" rel="noopener noreferrer" target="_blank">MMS MO Postbacks documentation</A></SPAN> for inbound group reply handling.</P> <H2>Call Flow and P2P Visibility Boundary</H2> <P><STRONG>Sending (MT)</STRONG>: Group messaging is implemented as a fan-out of individual MMS requests, not a single multi-recipient send. To deliver the same message to every participant, one request must be sent per recipient, rotating which number is the active recipient and which numbers are marked display-only. See the <A href="https://developers.sinch.com/docs/mms/7-service/mm7_submit" target="_self">MM7 API</A> developer documentation for the required request structure.</P> <P><BR /><STRONG>Receiving (MO)</STRONG>: When a participant replies to the group, Sinch receives the reply only if it is addressed to your provisioned number. The postback includes the participant roster as display-only numbers, so you can reconstruct who else is in the thread.</P> <P><BR /><STRONG>Where visibility ends</STRONG>: A reply within a group thread is delivered by the handset to all thread members at once. The leg addressed to your number comes to Sinch as A2P traffic. The legs addressed to other participants travel directly carrier-to-carrier as P2P traffic and never reach Sinch. If two participants exchange a message without your number remaining part of that specific exchange, Sinch has no record of it — this is consistent with the Person-to-Person Messaging behavior described below, where P2P traffic bypasses A2P-level handling entirely</P> <H2 id="MMSGroupMessagingonMM7API-Overview:">Compliance Concerns:</H2> <H3 id="MMSGroupMessagingonMM7API-HonoringUserOpt-Out">Honoring User Opt-Out</H3> <P>In accordance with Messaging Principles and Best Practices, content providers must establish systems that allow consumers to opt out of A2P messaging. Users should be able to unsubscribe using keywords such as STOP, END, UNSUBSCRIBE, CANCEL, QUIT, or phrases like "Please remove me" or "Stop sending messages." Once opted out, users must be quickly removed from the messaging list, and the content provider should cease all communications, sending only a final confirmation message of the opt-out.</P> <P> </P> <H3>Person-to-Person Messaging</H3> <P><SPAN>In group chat messaging, if a user wishes to be removed from a group chat, they may still receive unwanted messages from other participants who continue to respond to the old thread. This means that even after a user has opted out of receiving messages from the content provider, they might still receive replies from other group members. Since P2P messaging involves a direct route through carrier networks with minimal intermediate handling, the ability to impose additional restrictions specific to A2P communications, like blocking or content filters, does not exist in the P2P model.<BR /></SPAN></P> <P> </P> <H2><SPAN>Use-Case:</SPAN></H2> <P><SPAN>Group chat messaging, while an essential communication tool, presents unique challenges, particularly in larger groups. The high volume of messages can overwhelm users, causing important information to get lost in the clutter. Moreover, not every messaging need is well-suited for group chat messaging. However, there are several use-cases where group messaging excels:</SPAN></P> <P> </P> <P><STRONG>Project Collaboration</STRONG></P> <P><SPAN>Enables team members to discuss projects and stay updated in real time, fostering a collaborative environment that enhances productivity and speeds up decision-making.</SPAN></P> <P> </P> <P><STRONG>Real Estate Updates</STRONG></P> <P><SPAN>Realtors can efficiently keep potential buyers up-to-date with the latest listings, open house schedules, and other relevant news, streamlining the communication process in a dynamic market.</SPAN></P> <P> </P> <P><STRONG>Home Security</STRONG></P> <P><SPAN>Security companies can instantly notify homeowners of security alerts, whether at their residence or place of business, ensuring rapid dissemination of critical information for immediate action.</SPAN></P> <P> </P> <P><STRONG>Automotive Insurance</STRONG></P> <P><SPAN>In the event of an accident, insurance companies can use group messaging to coordinate communication between the driver of the vehicle, insurance agent, tow service, and interested family members, simplifying the management of the incident and support processes.</SPAN></P> <P> </P> <P><SPAN><STRONG>MM7 Group MMS Request Demo</STRONG>: From Submission to Handset Delivery<BR /><A href="https://clxgroup-my.sharepoint.com/:v:/r/personal/bhaqat_on_sinch_com/Documents/Videos/Clipchamp/Video%20Project%202/Exports/Group%20MMS%20Submission%20Demo.mp4?csf=1&web=1&e=ZkMGod" target="_blank" rel="noopener">Group MMS Submission Demo.mp4</A><BR /><BR /><BR /></SPAN></P> <P> </P> <DIV id="awebChromeHelper"> </DIV> Wed, 12 Aug 2026 22:41:21 GMT Keenon_House 2026-08-12T22:41:21Z Support for Group Messaging on 10DLC https://community.sinch.com/t5/MMS/Support-for-Group-Messaging-on-10DLC/ta-p/9279 <P> </P> <DIV id="awebChromeHelper"> </DIV> Wed, 12 Aug 2026 22:41:21 GMT https://community.sinch.com/t5/MMS/Support-for-Group-Messaging-on-10DLC/ta-p/9279 Keenon_House 2026-08-12T22:41:21Z