Add participants to an existing group message

H1290 wrote:

Yes, if everyone in the group has iMessage turned on*, and the group has 3 or more people. If someone has iMessage turned off, or is using a non Apple device, a new group must be created to add the people left out.

Yes, that is correct.

*According to this, everyone simply must own an Apple device. I am not 100% sure if turning off iMessage affects anything, but I think it does. Someone correct me if I’m wrong.

The paragraph in the Support article is a bit confusing. However, the relevant paragraph starts off, "With iMessage..."

If anyone in the group is NOT using iMessage (even if they have an Apple device), you're out of luck.

yes, everyone must own an Apple device to use iMessage as Group iMessage.

otherwise, the system defaults it to SMS and individual users will get separate SMS even though you try and send it as one message to a bulk list of recipients in the To list

Hello!

Yes, if everyone in the group has iMessage turned on*, and the group has 3 or more people. If someone has iMessage turned off, or is using a non Apple device, a new group must be created to add the people left out.

*According to this, everyone simply must own an Apple device. I am not 100% sure if turning off iMessage affects anything, but I think it does. Someone correct me if I’m wrong.