Unable to text in group chat

If you’re part of an iMessage group and suddenly can’t send messages to that group, it usually means one of the members has switched to an Android phone while keeping the same phone number. When that happens, the group falls back to SMS/MMS. If your carrier plan doesn’t include SMS/MMS for that SIM, your messages won’t go through.

• An iMessage group works only if all members are using Apple devices with iMessage enabled.
• If one member switches to Android and keeps the same phone number, the group automatically converts to SMS/MMS (the green-bubble life).
• Once that happens, your carrier’s SMS/MMS plan is required to send messages to that group.
• If your SIM doesn’t support SMS/MMS (or it’s disabled), you won’t be able to send messages, even though you were previously able to when it was pure iMessage.

Sometimes the issue can also be caused by a temporarily deregistered iMessage number or a network/carrier glitch—but in real life, an Android switch is by far the most common reason.

There are three types of group messages that you might see: group iMessage, group MMS, and group SMS. The Messages app automatically chooses the type of group message to send based on settings, network connection, and carrier plan. For example:

1. If you and your recipients are using Apple devices and iMessage is turned on, then the group message is sent as an iMessage. If you can't turn on or sign in to iMessage or FaceTime - Apple ... If you can't turn on or sign in to iMessage or FaceTime - Apple ...
2. If you send a group message to people who are on Android, then the message is sent as an MMS or SMS message. Check if you have an SMS plan enabled by your carrier for the SIM/eSIM that you use on your device.

Apple Inc. does not provide SMS services. You need to contact your Carrier to enable SMS and/or MMS.